Scratches on swim platform

STB · Apr 27, 2024

SteveK said:
STB. Care to share why you need to thin the gelcoat and even the video is unclear as to what thinness compared to the as is can of gelcoat. Use a syringe, then pour styrene (amount of each).

Can you compare to a liquid consistency we can relate to? Why is it not thinned to start with?

Hey Steve,

Out of the can, the viscosity is appropriate for application by brush or roller. It doesn't really flow out ridges to flat. And, it won't spray well, if at all. It mostly splatters.

Out of the can is fine, even beneficial, for a roller or brush because the goal is to over apply and then sand down and polish. With it more viscous, it stays put better.

To get a visual, see how the unthinned product, while very much a flowing liquid, stands up in a small puddle in this video, which is a companion to the other one I posted:

The thickness is thicker than whole milk but thinner than honey. Maybe as thick as a table syrup? It may depend a little on brand and temperature.

Even for paints like Perfection or Awlgrip, they get thinned differently (different thinner) for spraying than for brushing. The film thickness per coat and amout of flow expected is very different between the two methods of application.

It is hard to say how much I thin the gelcoat. 10% would be a good guess. I usually thin it until the viscosity seems to me to be a hair more than spray paint, then try it, then adjust in tiny increments until I like the flow.

I wish I could give you a good scientific answer, but I don't do this super super frequently and each time seems to be a little different w.r.t. how much gelcoat, how much pigment, how much thinner, the air temperature, the humidity, horizontal vs vertical, etc.

I mix it for color first, and place some directly on the boat to check, immediately wiping it off with acetone. Then, when I like the color, I thin and test spray onto cardboard. If I need to thin more, I do. One can make.more than needed and, if over thinned, just go back to the less thinned portion.

I always start by mixing more gelcoat than I'll put into the sprayer bottle. That way I can add some back if I over pigment. I have also added some back to thicken the coat for more coverage. But I then needed to deal with small amounts of pigment.

The thing I learned is that too much light is as bad as too little light for color matching. I really like indirect sunlight. Darkness poses an obvious problem. But on super bright days when the sun is right on the repair, I can't tell the difference between the shades very well. They all looks bright white. I end up seeing the repair later in different light and realizing give got to sand a bit and try again for the perfect color match. Obviously something can be used to variously shade the repair to check color originally. But I haven't been so good at that.

STB · Apr 27, 2024

paulga said:
If not using the smaller patch, I would need to buy a can of "one step finish" and some tubes of tint to use the sprayer. I wonder if a smaller can is available.

What tint are needed for different "grey scales" of white?

View attachment 154315 View attachment 154316

Hey Paulga,

They have kits that have a bunch of pigments. I've always used one of those. Total Boat or others may have more options w.r.t. size, possibly even in premixed colors that will get you close.

STB · Apr 27, 2024

STB said:
Hey Steve,

Out of the can, the viscosity is appropriate for application by brush or roller. It doesn't really flow out ridges to flat. And, it won't spray well, if at all. It mostly splatters.

Out of the can is fine, even beneficial, for a roller or brush because the goal is to over apply and then sand down and polish. With it more viscous, it stays put better.

To get a visual, see how the unthinned product, while very much a flowing liquid, stands up in a small puddle in this video, which is a companion to the other one I posted:

The thickness is thicker than whole milk but thinner than honey. Maybe as thick as a table syrup? It may depend a little on brand and temperature.

Even for paints like Perfection or Awlgrip, they get thinned differently (different thinner) for spraying than for brushing. The film thickness per coat and amout of flow expected is very different between the two methods of application.

It is hard to say how much I thin the gelcoat. 10% would be a good guess. I usually thin it until the viscosity seems to me to be a hair more than spray paint, then try it, then adjust in tiny increments until I like the flow.

I wish I could give you a good scientific answer, but I don't do this super super frequently and each time seems to be a little different w.r.t. how much gelcoat, how much pigment, how much thinner, the air temperature, the humidity, horizontal vs vertical, etc.

I mix it for color first, and place some directly on the boat to check, immediately wiping it off with acetone. Then, when I like the color, I thin and test spray onto cardboard. If I need to thin more, I do. One can make.more than needed and, if over thinned, just go back to the less thinned portion.

I always start by mixing more gelcoat than I'll put into the sprayer bottle. That way I can add some back if I over pigment. I have also added some back to thicken the coat for more coverage. But I then needed to deal with small amounts of pigment.

The thing I learned is that too much light is as bad as too little light for color matching. I really like indirect sunlight. Darkness poses an obvious problem. But on super bright days when the sun is right on the repair, I can't tell the difference between the shades very well. They all looks bright white. I end up seeing the repair later in different light and realizing give got to sand a bit and try again for the perfect color match. Obviously something can be used to variously shade the repair to check color originally. But I haven't been so good at that.

Looking at Total Boat's product, their instructions read, "Thin TotalBoat Gelcoat with styrene, only as needed (up to 15%, adding more can affect the color of the cured gelcoat)."

TotalBoat Gelcoat With or Without Wax | Marine Gelcoats

TotalBoat ISO/NPG neutral and white marine gelcoats compatible with coloring agents. Gelcoat available with and without wax for boat building and repairs.

www.totalboat.com

SteveK · Apr 28, 2024

Thanks @STB

STB · Apr 28, 2024

STB said:
Hey Paulga,

They have kits that have a bunch of pigments. I've always used one of those. Total Boat or others may have more options w.r.t. size, possibly even in premixed colors that will get you close.

Hi Paulga,

I guess I can add that I've always made the most use of white, black, red, and yellow.

paulga · Apr 28, 2024

STB said:
Hey Paulga,

They have kits that have a bunch of pigments. I've always used one of those. Total Boat or others may have more options w.r.t. size, possibly even in premixed colors that will get you close.

I saw this repair kit yesterday. is this kit what you mentioned? is it also applied using the same Preval sprayer?

STB · Apr 28, 2024

For what it is, that's as good a kit as any for doing it without a sprayer -- which is a perfectly viable option. I suspect you'd want more than the 1oz and also want reducer if you were to spray. They do sell a 4oz version.

The thing that I dont like about that kit -- and I'm sure is the source of most of the negative reviews it has (among many good reviews) is that it is an unwaxed gelcoat and doesnt include any PVA.

Unwaxed gelcoat is said to cure only in the absence of air (I think it actually has to do with off gasing certain important chemical(s) that exist in minute quantities, e.g. the catalyst(s), vs exposing to air, but same thing in practice). So it has to be sealed off completely or won't cure. This can be accomplished by covering the repair with a film (the included release film or wax paper, etc), ensuring that the are absolutely no bubbles and the repair is totally sealed. Or it can be accomplished by spraying on a sealant, most commonly PVA, which is available in tiny pump spray bottles.

I like PVA much better. It doesn't mess up my repair. When I used release sheets, I always feel like I need to make the repair thicker and wider to be able to squish it down while getting the air out.

In general, I use unwaxed gelcoat and PVA for deep fills and then waxed gelcoat and a sprayer for the top coat.

I don't know if I've ever been in that day, but if I didn't have any waxed gelcoat for the finish coats, I'd probably just spray unwaxed gelcoat and then use PVA.

I'd have to have a very large repair before I'd want to use sheets instead of PVA. Sheets have the advantage of being faster to remove from a large surface when done. PVA has to be cleaned off with (warm is better) water and a rag.

There are also wax additives and other release agent additives that can be added to vanilla gelcoat, but they can be harder to dose in small quantities, which is why I'd like to buy it that way or use PVA over the top.

With PVA, you want to apply it fairly promptly before the reducer evaporates out to any significant extent. If that happens the cross linking doesn't happen fully and it will never cure, remaining soft to sticky forever. People seem to do repairs then try to seal them with film or PVA or whatever hours later -- and then get shocked that it didn't work.

Why not try this...buy that kit and some PVA (poly vinyl alcohol, not wood glue). Do the repair by hand without a sprayer. You'll be fine, even if it takes a couple of tweaks to make it right.

Next time, add a sprayer and some more reducer to your toolbox. You'll already have the coloring agents. Try your hand at spraying. You'll have already practiced the fill and finish.

Doing it this way you can do your whole repair with that kit, a cheap thing of PVA, and the sanding and polishing supplies.

Don't make this a bigger deal than it is. I know it can all be intimidating with so many options and so much chemistry.

But once you get started, you'll practically be done! Really!

paulga · May 12, 2024

STB said:
You'll have to go touch it. It is hard from pictures. To me it looks like gel over fiberglass.

You can fix it by cleaning it out and then filling it with a resin-based repair putty from West Marine or similar, sanding to shape, and sanding past the damage, and then cleaning with acetone. From there you can apply your gelcoat.

They sell these very small sprayers that work with cartridge propellant. You can mix some gelcoat, tinting it a bit as needed, and spray it on. If the color isn't right, you can adjust a bit. Once ready, overspray past the edges of the repair. Get good coverage. Probably 4 or 5 thin coats.you can also brush it on.

Most gelcoat wont cure in the air, so the final coat needs a wax additive to make it self-sealing or to be covered tightly with a film. Once cured, finish sand and buff it.

Thickened epoxy can also be used, but is a bit more problematic. The bond is never quite as good as with resin and you need to clean it really well with water and a lightly abrasive cleaning pad before sanding and applying the gelcoat. This is to get off the amine blush, basically a water-soluable film that forms on the surface as it cures. Sanding before washing off the blush has a habit of pushing the amine carbamate into the texture from the sanding and making it harder to wash off. Since the amine blush is water soluble only water need be, or should be, used to clean it, but the cleaning step is important.

The process really isnt bad and can be done in a couple or few hours each day over a weekend. Total Boat and West Marine both have tutorials.

As with anything else, prep like masking and cleaning is as much of it as anything else. Ditto for the final sanding and buffing.

@STB I think the "... 4 or 5 thin coats" are applied continuously. The boatus video tutorial at 6:08 shows 3 layers applied continuously. or do you mean to wait for each layer to cure, then clean and sand using 220grit to 320 grit before spraying the next coat?

STB · May 12, 2024

I treat it like rattle can spray paint. I do immediate light overlapping passes, but I sort of consider than one coat.

But, light is the key. If you get it too thick, it'll run. That isn't terrible. You can just clean it, sand the runs, light sand, and overcoat if needed. Clean well to get the wax or PVA off or it won't lay or adhere well.

If you want additional coats, you can let it cure, clean it, light sand it, and apply more.

I actually consider it easier and more forgiving than spray paint. Once thinned, itnlays down about the same -- but itnis intended to get polished afterward to a high shine, so there is no harm in any minor contamination as it'll polish out.

Play with it on a piece if cardboard. You'll get the hang of it really quickly. Don't focus just on the boat. Have fun playing with it no-stakes first. Even a little practice will go a long way to having a confident technique.

That's my experience for whatever it is worth.

paulga · May 12, 2024

STB said:
I treat it like rattle can spray paint. I do immediate light overlapping passes, but I sort of consider than one coat.

But, light is the key. If you get it too thick, it'll run. That isn't terrible. You can just clean it, sand the runs, light sand, and overcoat if needed. Clean well to get the wax or PVA off or it won't lay or adhere well.

If you want additional coats, you can let it cure, clean it, light sand it, and apply more.

I actually consider it easier and more forgiving than spray paint. Once thinned, itnlays down about the same -- but itnis intended to get polished afterward to a high shine, so there is no harm in any minor contamination as it'll polish out.

Play with it on a piece if cardboard. You'll get the hang of it really quickly. Don't focus just on the boat. Have fun playing with it no-stakes first. Even a little practice will go a long way to having a confident technique.

That's my experience for whatever it is worth.

I was searching if there is PVA in a small spray pump like you mentioned. The one I found from amazon has bad rating about pva is too thick and it only squirts a small stream rather than a mist. But one feedback confirmed a PreVal sprayer can be used to spray PVA. so I can get Preval spare bottle or some touchup jars to switch quickly.

I have a question on the buffing step. I know my repair only requires a rag but just curious. The compounding pad used in the boatus video tutorial (the sprayer version that you posted) at 8:07 looks like a 9" 3M 05711, do you know which pad is a smaller equivalent, say 6", up to 8"

STB · May 13, 2024

Great questions!

Recall that when I, personally, spray a thin finish coat of gelcoat I used waxed gelcoat so I don't need to use PVA or sheets or anything else over the finish. I like it to stay just as I applied it. The wax mixed in prevents the off gasing of the catalyst (or "exposure to air"), enabling it to cure.

I used unwaxed gelcoat and pva if I do build ups in thicker layer(s) leading up to the finish coat. I've also used pva when applying unthinned gelcoat by hand, in which case I overfill just a hair so I can sand it down to blend. In other words, I use pva when I am using gelcoat that isn't super thin and thinned and will be sanded, e.g. filling a chip in the gelcoat (but not deeper), before spraying a thin coat to blend.

If you spray pva over a thinned top coat you risk the droplets displacing the topcoat. So, you'll want a really good sprayer and to go thicker so you can sand down. I'd want to avoid that complication and risk. It is ticklish.

I'd recommend spraying a thinned, waxed gelcoat. Or appling the unthinned, unwaxed gelcoat by hand and over spraying with pva. It isn't that you cant spray pva over thinned, sprayed gelcoat. It just gets to be quite and unnecessarily ticklish.

Also remember that gelcoat isn't a filler. It is relatively brittle and, if too thick, it cracks when flexed. Thick and thin here is relative to a coatings film thickness, not the depth of a fill. When aintalk about filling with gelcoat, I mean filling defects in the gelcoat itself, e.g. scratches or minor crazing, nit deeper defects into epoxy, resin, or glass layers.

For damage deeper than the original gelcoat, fill with a filler and/or otherwise repair first, and then topcoat with gelcoat and blend it in and polish it up.

As for the wool pad, there are different ways they mount. What device are you polishing with?

STB · May 13, 2024

I should also add that gelcoat does set up in a few minutes or so.

If you are spraying pva over thinned, sprayed gelcoat you need to be really careful to make sure the gelcoat has set first. If not, you'll have a muddy mess. Looking at reviews, it is pretty clear some people miss that step. Of course, if you wait an extended period of time before sealing off the uncredited gelcoat, it'll never cure.

You want to do the same when spraying pva over unthinned gelcoat, but it'll set faster and be a little more forgiving of being rushed.

Practice on cardboard. Try it waiting to long. Try spraying too soon. Try hitting it at afew times during the "right" window.

Have fun with it.

STB · May 13, 2024

Let me also comment on one more thing, but from scuttlebutt, not personal knowledge.

I've never user an expensive gun to spray gelcoat -- just those cheap ones.

But, those who have used expensive sprayers have told me that waxed gelcoat isn't their friend because if they don't clean their gun right away, it gets really, really hard to clean the tips. They are the ones I've heard of spraying pva over sprayed gelcoat. They feel it makes their life easier.

I think most hacks like me just use waxed gelcoat each time and start fresh without worrying about cleaning sprayer tips.

In any case, if you are going to spray pva over thinned, sprayed gelcoat, be really sure the gelcoat kicks before spraying the pva. If you do that, anything the pva does to the surface should polish right out.

I was reading some of the complaints for various products and it really does seem like folks aren't waiting for the gelcoat to kick before spraying the pva and maybe are expecting splattered pump bottle pva won't impact a super fine finish at all, and I wouldn't bet on that.

In any case, as long as you let the gelcoat kick before spraying the pva, and get a good film of pva over the top, whatever it does to the finish should polish right off. Just let it kick so you get pva over gel, not the two mixed.

paulga · May 13, 2024

STB said:
Let me also comment on one more thing, but from scuttlebutt, not personal knowledge.

I've never user an expensive gun to spray gelcoat -- just those cheap ones.

But, those who have used expensive sprayers have told me that waxed gelcoat isn't their friend because if they don't clean their gun right away, it gets really, really hard to clean the tips. They are the ones I've heard of spraying pva over sprayed gelcoat. They feel it makes their life easier.

I think most hacks like me just use waxed gelcoat each time and start fresh without worrying about cleaning sprayer tips.

In any case, if you are going to spray pva over thinned, sprayed gelcoat, be really sure the gelcoat kicks before spraying the pva. If you do that, anything the pva does to the surface should polish right out.

I was reading some of the complaints for various products and it really does seem like folks aren't waiting for the gelcoat to kick before spraying the pva and maybe are expecting splattered pump bottle pva won't impact a super fine finish at all, and I wouldn't bet on that.

In any case, as long as you let the gelcoat kick before spraying the pva, and get a good film of pva over the top, whatever it does to the finish should polish right off. Just let it kick so you get pva over gel, not the two mixed.

does let the "gelcoat kick" = wait for ~5 minutes (for the gelcoat to set up) ?

"...just use waxed gelcoat each time and start fresh without worrying about cleaning sprayer tips" -- I didn't get it. should it be "unwaxed" here? if waxed gelcoat make the tip difficult to clean, then it is important to clean the sprayer tips after each use, right?

paulga · May 13, 2024

STB said:
Great questions!

Recall that when I, personally, spray a thin finish coat of gelcoat I used waxed gelcoat so I don't need to use PVA or sheets or anything else over the finish. I like it to stay just as I applied it. The wax mixed in prevents the off gasing of the catalyst (or "exposure to air"), enabling it to cure.

I used unwaxed gelcoat and pva if I do build ups in thicker layer(s) leading up to the finish coat. I've also used pva when applying unthinned gelcoat by hand, in which case I overfill just a hair so I can sand it down to blend. In other words, I use pva when I am using gelcoat that isn't super thin and thinned and will be sanded, e.g. filling a chip in the gelcoat (but not deeper), before spraying a thin coat to blend.

If you spray pva over a thinned top coat you risk the droplets displacing the topcoat. So, you'll want a really good sprayer and to go thicker so you can sand down. I'd want to avoid that complication and risk. It is ticklish.

I'd recommend spraying a thinned, waxed gelcoat. Or appling the unthinned, unwaxed gelcoat by hand and over spraying with pva. It isn't that you cant spray pva over thinned, sprayed gelcoat. It just gets to be quite and unnecessarily ticklish.

Also remember that gelcoat isn't a filler. It is relatively brittle and, if too thick, it cracks when flexed. Thick and thin here is relative to a coatings film thickness, not the depth of a fill. When aintalk about filling with gelcoat, I mean filling defects in the gelcoat itself, e.g. scratches or minor crazing, nit deeper defects into epoxy, resin, or glass layers.

For damage deeper than the original gelcoat, fill with a filler and/or otherwise repair first, and then topcoat with gelcoat and blend it in and polish it up.

As for the wool pad, there are different ways they mount. What device are you polishing with?

I have a Bauer 5.7A short throw random orbit da polisher, it has a 6 in backing plate that supports up to 8" hook and loop polishing pad. I learnt some common pads from your video link and this post but those are 9" pads, so I was looking for smaller like 6" pads.

STB · May 13, 2024

paulga said:
does let the "gelcoat kick" = wait for ~5 minutes (for the gelcoat to set up) ?

"...just use waxed gelcoat each time and start fresh without worrying about cleaning sprayer tips" -- I didn't get it. should it be "unwaxed" here? if waxed gelcoat make the tip difficult to clean, then it is important to clean the sprayer tips after each use, right?

I am wasteful and just throw away the tips for the cheap sprayer. The folks with the good, real sprayguns obviously clean and reuse them. I've heard them complain that the waxed gelcoat gunks them up more. Like I said, those bits aren't first hand.

STB · May 13, 2024

paulga said:
I have a Bauer 5.7A short throw random orbit da polisher, it has a 6 in backing plate that supports up to 8" hook and loop polishing pad. I learnt some common pads from your video link and this post but those are 9" pads, so I was looking for smaller like 6" pads.

Can you post a picture of your polisher?

paulga · May 13, 2024

STB said:
Can you post a picture of your polisher?

here is a video:

STB · May 13, 2024

STB said:
I am wasteful and just throw away the tips for the cheap sprayer. The folks with the good, real sprayguns obviously clean and reuse them. I've heard them complain that the waxed gelcoat gunks them up more. Like I said, those bits aren't first hand.

Also, yes, it means waiting fornitntonsort of gel and get tacky. You can sort of see the change in the way it looks. If you don't mind leaving a bit of a print to sand/polish later, you can also touch it with a finger or toothpick

paulga · Jun 19, 2024

RT Firefly said:
Greetings,
Ms. p. With the greatest respect, one can do quite a bit of damage with a power tool IF one is not used to using it. Keep in mind that Bauer machine weighs 7.5 lbs and you will be hanging over the edge of the swim platform in an awkward position with a bulky unit attempting to work in a small area. I still suggest doing any sanding by hand. Not a large area so you can readily polish by hand, as well.

The Nashua waterproof tape is a pain to remove
It took quite some time to strip the aluminum off with a putty knife. The the sticky goo reminder does not come off. I have tried brushing with spray nine/alcohol/acetone, not effective.

Cancoon · Jun 20, 2024

paulga said:
One corner of the swim platform has had scratches from rubbing with the slip corner due to winds. Can this blemish be sanded off using Dremel oscillating tool with dark sand paper fine grit?View attachment 145028

I would try wet sandpaper 2000 or 2500 grit using a sanding block by hand. Hope this works for you.

paulga · Sep 16, 2024

STB said:
For what it is, that's as good a kit as any for doing it without a sprayer -- which is a perfectly viable option. I suspect you'd want more than the 1oz and also want reducer if you were to spray. They do sell a 4oz version.

The thing that I dont like about that kit -- and I'm sure is the source of most of the negative reviews it has (among many good reviews) is that it is an unwaxed gelcoat and doesnt include any PVA.

Unwaxed gelcoat is said to cure only in the absence of air (I think it actually has to do with off gasing certain important chemical(s) that exist in minute quantities, e.g. the catalyst(s), vs exposing to air, but same thing in practice). So it has to be sealed off completely or won't cure. This can be accomplished by covering the repair with a film (the included release film or wax paper, etc), ensuring that the are absolutely no bubbles and the repair is totally sealed. Or it can be accomplished by spraying on a sealant, most commonly PVA, which is available in tiny pump spray bottles.

I like PVA much better. It doesn't mess up my repair. When I used release sheets, I always feel like I need to make the repair thicker and wider to be able to squish it down while getting the air out.

In general, I use unwaxed gelcoat and PVA for deep fills and then waxed gelcoat and a sprayer for the top coat.

I don't know if I've ever been in that day, but if I didn't have any waxed gelcoat for the finish coats, I'd probably just spray unwaxed gelcoat and then use PVA.

I'd have to have a very large repair before I'd want to use sheets instead of PVA. Sheets have the advantage of being faster to remove from a large surface when done. PVA has to be cleaned off with (warm is better) water and a rag.

There are also wax additives and other release agent additives that can be added to vanilla gelcoat, but they can be harder to dose in small quantities, which is why I'd like to buy it that way or use PVA over the top.

With PVA, you want to apply it fairly promptly before the reducer evaporates out to any significant extent. If that happens the cross linking doesn't happen fully and it will never cure, remaining soft to sticky forever. People seem to do repairs then try to seal them with film or PVA or whatever hours later -- and then get shocked that it didn't work.

Why not try this...buy that kit and some PVA (poly vinyl alcohol, not wood glue). Do the repair by hand without a sprayer. You'll be fine, even if it takes a couple of tweaks to make it right.

Next time, add a sprayer and some more reducer to your toolbox. You'll already have the coloring agents. Try your hand at spraying. You'll have already practiced the fill and finish.

Doing it this way you can do your whole repair with that kit, a cheap thing of PVA, and the sanding and polishing supplies.

Don't make this a bigger deal than it is. I know it can all be intimidating with so many options and so much chemistry.

But once you get started, you'll practically be done! Really!

I thought to post an update here.

currently, I have applied the marine-tex and sanded it to 320grit. It already looks much better than before (see the attached photos). Next I'm going to sand it to 400 grit and apply the gelcoat repair kit.

To avoid more sanding, I prefer the spray method. I just came to know the gelcoat in the repair kit is a paste form, so it cannot be thinned and sprayed. I need to buy the liquid form gelcoat in order to spray it. Then I saw different options:

1. Evercoat one step premium gelcoat 1Pt $72 at West Marine
2. Total Boat Gelcoat 1 Qt $40
3. Fiberglass supply depot 1Pt $29

The Evercoat is the most expensive choice and the only option that says to "Reduce with Evercoat Acetone (10%) for sprayer applications" in the direction. Total Boat has the lowest price. They all have excellent feedback. why is Evercoat so expensive if they all work out the same @STB?

STB · Sep 16, 2024

Wow. Nice work. That looks 1000x better already! Go you!

As for the price tag, I think it mostly has to do with channels. Evercoat has a long history of being sold in high volume in small quantities retail. It is one of those products that pays West Marine's rent, etc. I suspect there are discounts in quantity for any professional that buys enough. But I dunno'.

TotalBoat's basic model is via the Internet. No retail rent to pay. But there might be shipping and a delay.

I wouldn't hesitate for 0.5sec using either. I've most often used Evercoat, just because WM has it on the shelf. But TotalBoat has always been good to me. It just requires I plan ahead, which I often dont.

I don't know much about what Fiberglass Depot sells. I've bought some supplies from them, but never coatings.

If it were me, and it were my first time, I'd probably use TotalBoat or Everclear.

Try the more unknown stuff next time, when you've done it with a more gold standard product once, just you know if anything is different than expected. Having said that, I think the videos were using a BrandX, I don't remember.

You'd probably be fine with any of them!

paulga · Sep 18, 2024

STB said:
Wow. Nice work. That looks 1000x better already! Go you!

As for the price tag, I think it mostly has to do with channels. Evercoat has a long history of being sold in high volume in small quantities retail. It is one of those products that pays West Marine's rent, etc. I suspect there are discounts in quantity for any professional that buys enough. But I dunno'.

TotalBoat's basic model is via the Internet. No retail rent to pay. But there might be shipping and a delay.

I wouldn't hesitate for 0.5sec using either. I've most often used Evercoat, just because WM has it on the shelf. But TotalBoat has always been good to me. It just requires I plan ahead, which I often dont.

I don't know much about what Fiberglass Depot sells. I've bought some supplies from them, but never coatings.

If it were me, and it were my first time, I'd probably use TotalBoat or Everclear.

Try the more unknown stuff next time, when you've done it with a more gold standard product once, just you know if anything is different than expected. Having said that, I think the videos were using a BrandX, I don't remember.

You'd probably be fine with any of them!

I read an article on how to apply gelcoat by layers, here are some takeaway points:

Apply gelcoat in 4-5 layers at approximately 5 mils each, allowing 15-20 minutes between layers for a total thickness of 20-25 mils for a proper cure
Sanding between coats is not necessary unless a surfacing agent has been added to your gel coat.
You should only use a wax additive in the final application coat or if you are planning on only one coat.

I think this is describing application on large areas, each coat is a new batch.

I also read this post and learned there is a Duratec High Gloss Additive. This additive seems to function both as a thinner to make gelcoat spray like paint, and as a surfacing agent to enable gelcoat to air cure. The direction also says to "Use a Non-Wax Gelcoat with this product", does this mean it contains wax?

Based on my understanding of these two articles, I plan to buy a can of Total Boat white no wax gelcoat and use a sprayer to apply 4 light coats to reach ~20mil thickness. First, make a large batch thinned with styrene (then tint and catalyst), apply 3 coats continuously without waiting in between. Then make a small batch adding ~15% Duratec, spray the final coat. after it cures overnight, do the polishing glaze etc. Have you used Duratec @STB ?

Not sure if i'm complicating this unnecessarily. My original plan was to buy a wax gelcoat and spray several layered coats and voila.

STB · Sep 18, 2024

I have never used Duratec. That's not to say that I think there is anything wrong with it. Its just that I first found a process using other product lines that worked for me, so I have stuck with one of them. It is certainly possible that, had I tried it first, I'd still be using it.

If you want to use that product line and don't know anyone who has experience with it, I'd call Fiberglass Depot's tech support and chat with them about the product. Coating vendors are usually super helpful when it comes to product support and they may have some "top pitfalls" they can steer you around.

Based upon my understanding, you are correct: No wax additive with Duratec (except in truly weird edge cases like trying to get it to cure underwater). It serves that purpose. I'm a little skeptical about mixing anything 1:1 with a coating not designed with that in mind. But, I have seen threads from folks that love it, and some of them have reported 50-50 and 60-40 mixes and excellent results. I think I remember some folks on The Hull Truth chatting about it.

I'm a little skeptical of any optional additive at those ratios. It isn't gelcoat. It is changing the properties somehow. And, that seems like a lot of change. I'm much more comfortable less than 10-15%. Its just seems to easy to find something with a different chemistry to matches initially, but age very differently. I'm thinking there is a lot of polyester in there and that the high gloss is coming from some dilution of the pigment, leaving it in some ways like a little bit of a clear coat. But, I don't know.

I've seen some gelcoat stay nice and white for decades, and others that yellowed in months to small years. My unsubstantiated guess is too much styrene wax, or similar. Those weren't Duratec applications, I don't think. But, there were, I think, examples of too much additive generating a nice initial result that didn't last.

...but, again, I have never used Duratec, so my skepticism is based upon nothing. If I'd used it first, and it make nice lasting repairs for me, I might be skeptical of using products with wax for fear of it yellowing!

The first time I heard how these preval spray repairs were done, it was from an employee at a West Marine near Los Angeles that fancied himself a fiberglass repair person. It isn't clear to me how skilled he actually was. But, he introduced me to the process and showed me some of his videos of doing it. At some point after that, I saw some more legit videos on YouTube. And then some folks who did a lot of that type of work dockside in the area told me it was legit and showed me some impressive quick repairs. I then did a bunch of repairs on what was then my boat, and since then have occasionally done some jobs for friends here or there. I'm not a super experienced professional. But, I'm determined, and I've always gotten really, really nice repairs in the end. And, you are well on your way to that type of really nice result, so, stick with it! Good work!

I guess my question for you is this, what advantage do you see in the Duratec product?

lwarden · Sep 18, 2024

West Marine sells a finish gelcoat which I've used successfully before. It's like a mixture of regular gelcoat and Duratec. I think the brand I've used from them in the past was called Evercoat, but it appears this is the same stuff under their label. It doesn't have the level of pigment as normal gelcoat so I generally do my filling first with thickened laminating gelcoat then spray this over the top. You can thin it a bit with a 50/50 mixture of styrene monomer and acetone to make it spray better. I haven't seen any yellowing on areas where it's sprayed. It still needs to be cut an buffed, but it sprays down with less orange peel so wet sanding and buffing is minimized.

Non-Laminating Finish Gel Coat | West Marine

Check out our Non-Laminating Finish Gel Coat and more from West Marine!

www.westmarine.com

paulga · Sep 18, 2024

STB said:
I have never used Duratec. That's not to say that I think there is anything wrong with it. Its just that I first found a process using other product lines that worked for me, so I have stuck with one of them. It is certainly possible that, had I tried it first, I'd still be using it.

If you want to use that product line and don't know anyone who has experience with it, I'd call Fiberglass Depot's tech support and chat with them about the product. Coating vendors are usually super helpful when it comes to product support and they may have some "top pitfalls" they can steer you around.

Based upon my understanding, you are correct: No wax additive with Duratec (except in truly weird edge cases like trying to get it to cure underwater). It serves that purpose. I'm a little skeptical about mixing anything 1:1 with a coating not designed with that in mind. But, I have seen threads from folks that love it, and some of them have reported 50-50 and 60-40 mixes and excellent results. I think I remember some folks on The Hull Truth chatting about it.

I'm a little skeptical of any optional additive at those ratios. It isn't gelcoat. It is changing the properties somehow. And, that seems like a lot of change. I'm much more comfortable less than 10-15%. Its just seems to easy to find something with a different chemistry to matches initially, but age very differently. I'm thinking there is a lot of polyester in there and that the high gloss is coming from some dilution of the pigment, leaving it in some ways like a little bit of a clear coat. But, I don't know.

I've seen some gelcoat stay nice and white for decades, and others that yellowed in months to small years. My unsubstantiated guess is too much styrene wax, or similar. Those weren't Duratec applications, I don't think. But, there were, I think, examples of too much additive generating a nice initial result that didn't last.

...but, again, I have never used Duratec, so my skepticism is based upon nothing. If I'd used it first, and it make nice lasting repairs for me, I might be skeptical of using products with wax for fear of it yellowing!

The first time I heard how these preval spray repairs were done, it was from an employee at a West Marine near Los Angeles that fancied himself a fiberglass repair person. It isn't clear to me how skilled he actually was. But, he introduced me to the process and showed me some of his videos of doing it. At some point after that, I saw some more legit videos on YouTube. And then some folks who did a lot of that type of work dockside in the area told me it was legit and showed me some impressive quick repairs. I then did a bunch of repairs on what was then my boat, and since then have occasionally done some jobs for friends here or there. I'm not a super experienced professional. But, I'm determined, and I've always gotten really, really nice repairs in the end. And, you are well on your way to that type of really nice result, so, stick with it! Good work!

I guess my question for you is this, what advantage do you see in the Duratec product?

since the gouges have already been filled, I think one coat is sufficient. My original plan is to spray a waxed gelcoat in overlapping passes and repeat several times. this is to continuously apply one waxed coat over the previous waxed coat. I'm not sure if this is correct.

because it was said surfacing additive should only be added in the final coat. It's difficult to dose wax additive to a small batch. while Duratec has a flexible mix ratio to gelcoat, from 15% up to 1:1, difficult to get it wrong. It also functions as a thinner, simplifying the process further. it also promised a high gloss finish after air cure. these make it sounds a good choice for additive.

paulga · Sep 18, 2024

lwarden said:
West Marine sells a finish gelcoat which I've used successfully before. It's like a mixture of regular gelcoat and Duratec. I think the brand I've used from them in the past was called Evercoat, but it appears this is the same stuff under their label. It doesn't have the level of pigment as normal gelcoat so I generally do my filling first with thickened laminating gelcoat then spray this over the top. You can thin it a bit with a 50/50 mixture of styrene monomer and acetone to make it spray better. I haven't seen any yellowing on areas where it's sprayed. It still needs to be cut an buffed, but it sprays down with less orange peel so wet sanding and buffing is minimized.

Non-Laminating Finish Gel Coat | West Marine

Check out our Non-Laminating Finish Gel Coat and more from West Marine!

www.westmarine.com

Evercoat premium gel kote (laminating gelcoat) is 2/3 of the price of their premium finish step gelcoat.
TotalBoat also has both gelcoat containing wax (14409) and without wax (488419) at the same price. It appears the gelcoat without wax the equivalent of Evercoat's laminating gelcoat

STB · Sep 19, 2024

paulga said:
since the gouges have already been filled, I think one coat is sufficient. My original plan is to spray a waxed gelcoat in overlapping passes and repeat several times. this is to continuously apply one waxed coat over the previous waxed coat. I'm not sure if this is correct.

because it was said surfacing additive should only be added in the final coat. It's difficult to dose wax additive to a small batch. while Duratec has a flexible mix ratio to gelcoat, from 15% up to 1:1, difficult to get it wrong. It also functions as a thinner, simplifying the process further. it also promised a high gloss finish after air cure. these make it sounds a good choice for additive.

I can't argue with your logic. Seems sound to me.

Is suggest hopping on Hull Truth or anywhere else you see a thread about it, even a dead one, and asking about single coat coverage.

The two things I wonder about are...

1) whether, if the gel is heavily diluted, it'll still be able to provide good enough 1-coar coverage, and

2) whether it kicks as quickly as a normal gel mix, allowing multiple coats quickly after each other, or if each coat requires more time.

But, again, I'm just wondering. I've never used it.

I look forward to your full report, whatever you use! Can't wait for the pics!

lwarden · Sep 20, 2024

If you just want to go with one gelcoat type then just use laminating gelcoat and do a spray of PVA over the final coat. No need to add wax to the final coat if you use PVA. I've done both adding wax to laminating to turn it into finishing gelcoat and spraying PVA over non-molested laminating, both work.

The only reason to use the finish gelcoat from Evercoat or the version West sells is it's easier to spray.

Scratches on swim platform

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Member

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Guru

Similar threads