Gelcoat over epoxy?
 

I read that it shouldn't be done, then I read from West system that it can be done. Anyone ever done it? I am rather heavily modifying my console and the patches will be epoxy. I don't want to spray a urethane like Awlgrip. Doesn't mean I won't, but I prefer to try gelcoat here. Especially as I will probably use it later on a molded part.

Basically I cut off the seat on the center console door and epoxy/glassed over it. A hack job, but I didn't have the luxury of time to do it nicely. And the epoxy allowed me to use XPS polystyrene to fill the hole and prop up the epoxy/glass during cure without dissolving, like if I used polyester.

The worst epoxy to try and gelcoat is west system epoxy
 

It is a high blush epoxy. Anyway. No matter which epoxy you use. You can still gelcoat. If it is a blushing epoxy like west then make it blush, That means forcing the amine solution out rather then it coming to the top later and lifting the gel coat. I used to gel coat west system all the time. Then lightly sand and gelcoat. Now I use much cheaper USComposites epoxy and have never seen it blush in 10 years.

Thanks!

Well, the hardener is ancient (but free, along with the resin- which is nice) so I mixed it 10% hot on hardener, so there is even more amine than usual. But the next layer I will mix correctly.

Good to know. It is just a door, so it is a great place to experiment. I plan or brushing on the gel coat. Along with the touch up on the console proper.

Next on the list is a vacuum bagged fuel tank hatch (mine is a resin rich pig of a thing) and splashwell for a master angler 20, as I can't find one. Probably epoxy/carbon with gel coat. Or vinylester/carbon.

If I remember this sequence properly.After two days or more of curing.
 

If it has not blushed on its own? It usually happens very quickly in spring weather conditions. To mimmic that I think I warm it a bit with a heat gun or quartz light. then spray it with some water and let it cool and sit over night. Then warm one more time the next day if it has not blushed. sometimes it takes a second try to get it out. Just wipe with clean rags and let dry and then sand a little bit.

excellent advice jay

a guy i know,"mad mike" - he plays WAY above his skill level - he grabbed some products from me to make "gutters" on his shamrock - a few days later,he returned and complained "that stuff you gave me never set up" !? - i asked him what happened and how he applied it - he explained...the i aksed him if he removed the blush from the epoxy ? i got the blank stare...
he used west system,and he was also using a chopped strand putty over the west...not really sure how he made out with the mess he created - somethings are better unseen...

I can help on thi one :)

gelcoat/polyester WILL cure over some epoxies. You have to make certain its compatible. The epoxy has to be completely cured too.

Do not mix epoxy outside of its designed ratio (hot), all your doing there is introducing more hardener molecules than needed and the epoxy will not cure fully or even at all. The hardener in epoxy is not just a "catalyst" like in polyester, its actually part of the combined epoxy molecule. Catalyst for poly basically "tells" the polyester molecules its time to become hard. Epoxy resin and hardener are more like couples at a dance, mix in too many males or females and you end up with leftover resin or hardener with no where to go = soft epoxy.

I am getting closer to gelcoat time. It is slow going borrowing a basement in winter to do mods.

I know enough to spray PVA on after the gelcoat so it cures. But How thick can I put the gelcoat on. What i sanded off was probably .04-.06" thick? Not much more than 1/16". I am wondering how much I can hide? And are there gelgoat thicknesses/viscosities I should be looking for, like runnier versus thicker? I am wondering how much 1708 biax print-through I can cover up.

This outer layer has the right resin ratio with the slower hardener- a 40 minute plus pot time is much nicer to work with. I plan on sanding with 40 or 60 grit and sandblasting where I can get away with it. I assume it can cover this?

I am going to re-use the bottom of the original seat as a hatch and make the door semi-permanent and a 150 quart cooler as a seat instead. I got tired of opening the giant door in the smallish 20 foot master angler for every little thing.

Is there someplace other than We$$$t Marine wher I can get gel coat retail for under $50/ qt?

That's the Woburn, MA price. I might want to apply it this weekend, so mail order isn't gonna do it.

Look up compatible gelcoat on line and take ad pricing into West Marine..they will match it!
Just make sure it is the same that West Marine is selling...I do this frequently......
Looks like you might be limited to Evercoat on the gelcoat though

-Fred

interesting thread . im making a bait tank buiklt out of wood i want ot glass it and watvhin ght e west systen videos they dont show how to coat the wood with the epoxie then lay the glass mat and expoie it but dot show how to do a finnish coat. i read somthing that soulde dlike just to paint it as in bottom paint on the huill or a epoxie paint abouve water what is the best way to achieve a nice white tank? ive never tried this type of project before but with the properinfo im sure i can

Back in the day we had no problem with the left over females :)

strick

The guys at Merton's were telling me not to try gelcoat over epoxy. They were trying to be helpful, and I appreciate that, but I will probably still try it anyways, I found some West marine coupons. I will do a test panel this weekend.

Maybe a test panel next weekend. Have been block sanding this weekend. Not too bad to hand sand with a 36 grit long board with micro-balloons and epoxy, but not a lot of fun.

Blue sharpie marker spots where I need to fill a little more.

The bare patch in the middle will be a hatch for the console, so I don't have to swing it on the hinges to get to storage. That will also be my West System to gel coat compatibility test panel.

another good tip,when applying gel over epoxy:

i like and use duratec surfacer - it's a two fold - it fills the pin holes and,it provides a seperation coat - spray the duratec,let it kick,sand,and spray on the gel - i use epoxy on just about every repair i do - this is the method i use...

I guess I will have to order some. I keep hearing about it here, and a primer/filler/surfacer can't hurt. Looks like mail order from Express Composites, unless there is someplace local north of Boston.

The vinylester duratec came in this week, haven't even opened the box. I hate sanding with a longboard. Especially when I screw up and put down too much fairing compound. Oh well, it will look nice.

Get it from www.mertons.com he's in springfield Ma and he carries a very good quality gelcoat.$21.75 per quart and 62.95 per gallon.He ships the same day and your a one day delivery.Order it now and you'll have it ups tomorrow.He'll be closed tomorrow(friday 4/6)Tell him I (John) sent you

Well, I am finally getting close to gel coat. I have to address a bunch of "bullet holes" in the console, too. Plus the old gas filler hole in the cap. I filled them with JB-Weld to start. I will probably do one more batch of microbaloons and West System.

but you can see the lack of seat on the console door, finally. Now there is room to move around up there. htat's where the $80, 150 quart cooler goes. The yet to be cut out hatch should be about where one's shoulder blades are.

Oh yeah, a new instrument panel of okume is going in, too, alone with new fuse panels, radio and GPS.

With the tall Master Angler cap and no windshield, it looks like a mini cigarette boat on the trailer. :D

Working in the new dash panel, too. She likes it when I do woodworking in the dining room :D

Gel Coat over epoxy
 

WillyC and I both did Gel coat over Raka epoxy (his hull bottom and my console). Both of us used Duratec which definitely makes for a shiny finish, but since the Duratec is clear and replaces some of the gelcoat (and therefore some of the pigment), it seems to be a little more difficult to cover repairs without seeing through it. Even though it sprays quite nicely with a regular gun (not so nice in a gel-coat gun we found out), it ends up being kind of a pain because you need it thick enough to cover well, but if you put it on that thick, it runs BAD and sanding out runs without burning through the surrounding area is very very difficult (at least it was with my 6" sander). It took multiple coats. The results were beautiful but it is definitely alot of work. I guess one positive is that it is not as likely to kill you as spraying two part epoxies. Here is a before and after with epoxy and gel-coat.

Nice work!

I just got done with my Duratec vinylester primer experiment. It kicks quickly and sticks to anything. I stuck it to high microbaloon content epoxy (a no-no) and gel coated over top of it and it all seems good so far. And the vinylester primer is high build. .040" per application! I put it on with a roller and it left a texture in the most wicked way, as I couldn't let it just lie flat, plus I ran out of short nap rollers. It just about matches the stock(?) off white/light sand color in my 1974 Master Angler. I wish I had sprayed it, as I would have just left it. It matches the existing oxidized gelcoat pretty well.

for best results,duratec should be sprayed,not rolled or brushed...