Polyester Resin dye

[Hermit Scott]

I am finishing filling in the ports on the outside of one side of the boat. The other side still has a lot to be filled and faired. This has been a lot of work.
I am going to paint the deck one of these days(hopefully this winter or spring). So I don't want to put any paint over the fiberglass work just yet because I am not sure what paint I am going to use and don't want compatibility issues. The rest of the boat is gelcoat.
I want to add dye to polyester resin and 'paint' over the new fiberglass work with it. Has anyone done this. I see at defender they have resin dye. Is there any trick I should know? Mixing ratios? What does it end up looking like?

 

[Ross]

I have mixed small quantities of resin and universal colorants from a paint store with success. Generally you need a base pigment plus color for larger quantities.

 

[Hermit Scott]

I have mixed small quantities of resin and universal colorants from a paint store with success. Generally you need a base pigment plus color for larger quantities.

what do you mean by 'a base pigment plus color'? I want to make it white. Is there more than one dye type that I need? I don't need much, 8 oz. should cover those ports on that side.
what brands did you use?

 

[Tim Huss]

I would just prime it with duratec its a heavy body primer that is easy to sand you will have a better finish annd it sands much better then resin it should be compatable with most any marine or auto paint. it can be polished up very well and will give you a nice end result! here is a link for a good tutorial and lots of other good stuff

· www.fibreglast.com/product/LC_006

 

[Old Skool Neil]

Why not use gelcoat? It's essentially pigmented resin. You might need to thin it a little and you'll have to add surfacing agent but it seems to me to be ready made for your needs.

 

[Ross]

what do you mean by 'a base pigment plus color'? I want to make it white. Is there more than one dye type that I need? I don't need much, 8 oz. should cover those ports on that side.
what brands did you use?

Just go to your local paint store and tell them what you need. it doesn't take much color to change clear resin to colored paint.

 

[RichH]

Just go to your local paint store and tell them what you need. it doesn't take much color to change clear resin to colored paint.

..... or just buy gelcoat already colored/pigmented WHITE. Tint to the 'hue' that matches your OEM Gelcoat - simple.

 

[Neil McDonald]

Tinting Gelcoat

..... or just buy gelcoat already colored/pigmented WHITE. Tint to the 'hue' that matches your OEM Gelcoat - simple.

Make sure that the area of OEM gelcoat that you reference for the tinting process is thoroughly clean or you will not be matching the true hull colour. 600 wet or dry emery cloth on a small section should do the trick.

 

[Hermit Scott]

My boat is ugly(in need of paint). I don't need to get it perfect with gelcoat. I was hoping to just have something easy that I could put in the resin I am already going to be painting over the fiberglass work already done.
I really am going to paint it one day with a two part like perfection or maybe spray emron. I won't try gelcoat.
I am trying to be realistic about getting this done, and not try to get into gelcoat since I am not going to be using it anywhere else. What I mean is I don't want to add anymore complication to this project because it has already taken over a year just to get this far with it.
Mainesail said I would regret it. I don't yet, but not far from it. If I would have known before I started just how many hours this would take, I seriously doubt I would have started.
After finishing the inside, I don't want to put any ports in the cabin area again. I know it seems weird to everyone but I like the cave feeling to it.

 

[Hermit Scott]

Just go to your local paint store and tell them what you need. it doesn't take much color to change clear resin to colored paint.

I have no confidence in counter help. Every once in a great while I will run across a knowledgeable counter person. I cherish those moments.

 

[Steve Dion]

If you are going to do the entire hull, why do you need to worry about color matching? I bet you can get the original color directly through Catalina if that is an issue.

Is there a major difference is spraying gel-coat versus paint. I have seen a lot of paint jobs that look worse than nasty old gel-coat so be careful on what you wish for.

 

[Ross]

I have no confidence in counter help. Every once in a great while I will run across a knowledgeable counter person. I cherish those moments.

There are company owned and run paint stores and those are the ones to shop. Name paint brands and some market their paint from their own stores.

 

[Hermit Scott]

If you are going to do the entire hull, why do you need to worry about color matching? I bet you can get the original color directly through Catalina if that is an issue.

Is there a major difference is spraying gel-coat versus paint. I have seen a lot of paint jobs that look worse than nasty old gel-coat so be careful on what you wish for.

The difference in spraying gelcoat and paint is the level of difficulty. Done right, either one will look great. Done poorly either one could look like disastrous.
I would not attempt to spray the entire deck with gelcoat. It's just too difficult for me. I want to dye the resin in case I don't get to paint her this year. From the distance of the sidewalk, dyed gelcoat may look acceptable. Right now it is dark green nastiness.
If I can't dye the resin, I will have to leave it dark green until I get it painted. Because I don't want to risk painting it with something that is incompatible with whatever I end up painting it with.

 

[Hermit Scott]

This is what it looks like now except sanded flat. Sooo I think it would be a little better if it were some hue of white instead of this.

 

[Barnacle Bill]

I assume you filled your ports with something more than polyester putty, but with layers of fiberglass laminates (cloth, mat, etc.). When you color resin, you don't get a great opaque color. You are actually better off using gelcoat. Gelcoat is a polyester product too. Don't be afraid of it. Someone said go to the paint store and get some paint to apply in that area. No, no, no. It is ok to paint the whole deck or boat, but not just an area. You can buy white gelcoat with wax in it so it will cure without covering it with plastic or spraying a mold release (PVA) over it to cure it. It will cure on its own, if it has wax. You can simply paint it on with a brush after you catalyze it. You use about 10 to 12 drops of MEKP to each ounce of gelcoat (this is a little hotter than resin). Figure an ounce is about a golf ball size. Mix it in a paper cup and use a cheap, disposable brush, and brush it on. If you want to thicken it up a bit, you can use cabosil. After it cures, it is sandable. I would actually take a polyester putty to smooth out your repair job and then clean it with acetone after you sanded it with 80 grit sandpaper. Then paint on the gelcoat. If you want to spray it on, you can go to an automotive store and buy a Preval sprayer, which is a little powerhead unit that screws onto a glass jar. Put the gelcoat in the jar (it holds up to 5 or 6 ounces) and then catalize it with the MEKP. Then you must thin it with acetone so it sprays out nicely and then paint the area. The spray pattern is not very big, but it works. It will be a smoother application than brushing. But, remember, brushing it on thick will give you enough substance to sand. Use 320 grit wet paper, then 400, then 600 and then after that you can actually buff it out with a fiberglass rubbing compound. Even if you don't want to do the sanding and buffing, I think you will find brushing on the white gelcoat will satisfy your needs based on what I have read. If the white gelcoat is not exactly the color white you need, you can use small amounts of colorant to match the gelcoat on the rest of your deck. Good luck.

 

[Ross]

Reading comprehension seems to be in short supply these days. There is a great difference between going to a paint store and buying paint and getting a small supply of universal colorant to add to the resin. Even if you get white gelcoat you will still need a bit of color to tint the white.

 

[John Howitt]

use the universal colourant(as Ross said). mix it in with the resin and use a thickener.(as Bill said) applly and sand smooth. It will appear somewhat white.
Then use the Waxed gelcoat. and spray it on thick , maybe several coats, no sanding or cleaning in between if you do them quickly, the sprayer costs about ten bucks.
Getting the exact colour match is a a bit of an art, but close is easy.
Easy job

 

[Hermit Scott]

I assume you filled your ports with something more than polyester putty, but with layers of fiberglass laminates (cloth, mat, etc.). When you color resin, you don't get a great opaque color. You are actually better off using gelcoat. Gelcoat is a polyester product too. Don't be afraid of it. Someone said go to the paint store and get some paint to apply in that area. No, no, no. It is ok to paint the whole deck or boat, but not just an area. You can buy white gelcoat with wax in it so it will cure without covering it with plastic or spraying a mold release (PVA) over it to cure it. It will cure on its own, if it has wax. You can simply paint it on with a brush after you catalyze it. You use about 10 to 12 drops of MEKP to each ounce of gelcoat (this is a little hotter than resin). Figure an ounce is about a golf ball size. Mix it in a paper cup and use a cheap, disposable brush, and brush it on. If you want to thicken it up a bit, you can use cabosil. After it cures, it is sandable. I would actually take a polyester putty to smooth out your repair job and then clean it with acetone after you sanded it with 80 grit sandpaper. Then paint on the gelcoat. If you want to spray it on, you can go to an automotive store and buy a Preval sprayer, which is a little powerhead unit that screws onto a glass jar. Put the gelcoat in the jar (it holds up to 5 or 6 ounces) and then catalize it with the MEKP. Then you must thin it with acetone so it sprays out nicely and then paint the area. The spray pattern is not very big, but it works. It will be a smoother application than brushing. But, remember, brushing it on thick will give you enough substance to sand. Use 320 grit wet paper, then 400, then 600 and then after that you can actually buff it out with a fiberglass rubbing compound. Even if you don't want to do the sanding and buffing, I think you will find brushing on the white gelcoat will satisfy your needs based on what I have read. If the white gelcoat is not exactly the color white you need, you can use small amounts of colorant to match the gelcoat on the rest of your deck. Good luck.

the problem I have with using gelcoat is, I am unexperienced with it, and I don't want to brush it because it is impossible to get a consistent thickness while brushing on. Too thick of gelcoat is a major cause of cracking. If I was doing a very small spot then I might be able to get away with it, but this is too many square feet. Just because it's polyester based does not mean it is interchangeable with polyester resin.
My only options are 1.leave it ugly 2. dye the resin 3.paint it with a compatible paint that will accept other paints like emron or two part paints. It is likely that when I go to paint it, any bare polyester or epoxy resin will have to be primed with something first. BUT I can't just prime it because primers are designed to absorb. I won't leave primer spots to absorb water while I wait to paint it.

There are many pounds of 24oz. 10 oz. and chopped strand in there. The green is short haired polyester to fill and fair around the edges of the fiberglass panel. I posted a lot of pictures as I went along. It was a nasty , nasty mess inside. It came out ok inside. It was much easier to work inside the boat on the relatively flat surface than on the outside curves.
The inside had to get finished first anyway so we could use it. The outside is just a matter of looks.

 

[Tim Huss]

if you just are worried about cosmetics rolling thinned down gell coat will work just fine use a fine roller and make sure you spread it out well!

 

[Maine Sail]

Just go to your local paint store and tell them what you need. it doesn't take much color to change clear resin to colored paint.

Reading comprehension seems to be in short supply these days. There is a great difference between going to a paint store and buying paint and getting a small supply of universal colorant to add to the resin. Even if you get white gelcoat you will still need a bit of color to tint the white.

Ross,

Paint store "universal colorant" should not be used with polyester resin or gelcoat. You will ruin the batch if you try and use pigment / tint made for paint.

Gelcoat & resin pigments are made specifically for use with resins or gelcoats and are usually made from a raw polyester resin base but lack the promoter agent , normally cobalt, which reacts with the MEKP. They need to be chemically compatible with the resin or gelcoat so that cross-linking occurs, paint pigments are not.

As for tinting the resin I would not bother. You can not add enough pigment, by volume, without inhibiting the cured structure of the resin to make it completely opaque. Yes, tinting can minimize bleed through on a thin coat of paint or gelcoat but properly applied gelcoat or paint will not have any problem hiding the substrate.

Rolling on gelcoat with a West Systems foam roller is easy. It will not lay down perfectly flat but can then easily be wet sanded and buffed to a factory looking finish.

I would roll two coats of un-waxed gelcoat then follow it up with a waxed layer. Let kick off in-between coats about 20-30 minutes depending upon temp then apply the next coat. The final coat that contains the wax will allow a full cure.

You could also use a product like System Three WR LPU which is a water based LPU paint, Interlux Perfection, or a single pack paint if durability is not your main concern.