if I wanted to gelcoat my deck...

[F14CRAZY]

I'd have a few questions...

So as you guys know I'm doing new stringers and decking in my Capri. I'm undecided on how I'd like to cover the new deck though.

If I wanted to gelcoat, as I understand it, I would put a layer or two of light fabric down with polyester (NOT epoxy, because gelcoat won't chemically bond to epoxy), then apply gelcoat, then sand to my liking...

-How do you go about doing the corners and edges? I know modern boats have molded corners and edges...while I don't exactly want to go that far, would I fill up the edges and corners with thickened polyester resin and maybe sand until I get a nice, gentle angle?

-Is gelcoat sprayed or can it be rolled on?

-when cured, what's its texture? I would like a fairly smooth surface but with a tiny bit of roughness for traction (along the lines of sand)

 

[Bondo]

Re: if I wanted to gelcoat my deck...

Ayuh,...

Gelcoat is basically a Colored poly Resin,....That's It....

 

[Mark42]

Re: if I wanted to gelcoat my deck...

Thin it and it can be sprayed, or just roll on. Different texture rollers will give different amouts of non-slip. Thinned and rolled, it will self level. The last coat you can mix in grit like play sand (its clean and uniform). Probably best to play around with some test batches.

I have been going to the manufacturers websites and downloading their directions on how to use it.

 

[F14CRAZY]

Re: if I wanted to gelcoat my deck...

thanks for the input guys, I may go this route. It's between this and snap in carpet with the deck sealed with unpigmented epoxy and a couple layers of thin glass and painted.

 

[oops!]

Re: if I wanted to gelcoat my deck...

-How do you go about doing the corners and edges? I know modern boats have molded corners and edges...while I don't exactly want to go that far, would I fill up the edges and corners with thickened polyester resin and maybe sand until I get a nice, gentle angle?

-Is gelcoat sprayed or can it be rolled on?

-when cured, what's its texture? I would like a fairly smooth surface but with a tiny bit of roughness for traction (along the lines of sand)

uh....little more to it than that crazy...

gellcoat is very thick......"thixotropic".

what you will have to do is after glassing the deck with 2 layers of csm...(use the traditional fiberglass-plywood sealing techniques

the final layer of glass should be the thin 8 oz finishing woven cloth......called a finishing veil. and use more resin....(up to a 70-30 ratio)
after thats cured...take a sander over it and knock down all high or rough spots left from the glassing, and make the glass smooth....(non waxed)

if you want....you can add peanut butter to the edges and sand it down so its smooth........finishing sanding is the key. everythings jotta be right.....the resin spreads just like a thick paint.

spraying is the best........but rolling is great too.......you want many coats and for it to go on thick......it wont self level.....and you dont want to thin it at all........a minimum of three coats will give you a good looking deck.....for the final layer......there is some sand like stuff you can add.....but a really thick roll job will give you a pebbeled surface that you can walk on, and is still shiney enough to look good.

hope that helps
cheers
oops

 

[Mark42]

Re: if I wanted to gelcoat my deck...

uh....little more to it than that crazy...

gellcoat is very thick......"thixotropic"......


spraying is the best........but rolling is great too.......you want many coats and for it to go on thick......it wont self level.....and you dont want to thin it at all.......

hope that helps
cheers
oops

Hey oops! Hows those temps up north? Its been so cold here I just read to pass the time until spring.

I've been reading the application methods from various gel coat manufacturers. Although all indicate their gel coat is thixotropic (won't run on vertical surfaces), more than one lists their gel coat as "self leveling" and so far all I read list thinning with styrene at up to 15% as acceptable, especially when spraying. They indicate that other chemicals have been added for leveling and "flow out".

Given the above, I see no problem with thinning to get better self leveling and flow out if you don't like those properties when applied straight. Especially when used on horizontal surfaces like decking.

The more I read, the more I plan to gel the deck in my Bayliner. I think I'll replace the carpet on vertical sides of the hull with a marine deck vinyl like deco dot.

 

[oops!]

Re: if I wanted to gelcoat my deck...

Hey oops! Hows those temps up north? Its been so cold here I just read to pass the time until spring.

I've been reading the application methods from various gel coat manufacturers. Although all indicate their gel coat is thixotropic (won't run on vertical surfaces), more than one lists their gel coat as "self leveling" and so far all I read list thinning with styrene at up to 15% as acceptable, especially when spraying. They indicate that other chemicals have been added for leveling and "flow out".

Given the above, I see no problem with thinning to get better self leveling and flow out if you don't like those properties when applied straight. Especially when used on horizontal surfaces like decking.

The more I read, the more I plan to gel the deck in my Bayliner. I think I'll replace the carpet on vertical sides of the hull with a marine deck vinyl like deco dot.

hi mark.....its too freeking cold up here....we are still under snow....and the boat has a big mound of snow on it....im ready to go crazy from not working on it !

self leveling gellcoat is a dream the manufacturers are trying to attain.....
it is thinner than ketchup but thicker than oil.

when sprayed...you have to thin it to get it out of the nozzle......products like patch aid really help with that....also doing repairs it is very important.
as you want a flat smooth repair that requires little sanding to get it to the substrate surface depth. uasually gellcoat is thinned with aceitone. if i remember correctly....10 % is max....(dont quote me on that cause im having a "rough" day today )....one of the great dangers of thinning a product is that its really easy to thin too much to make it come out of the gun better....but after the 10% the gellcoat looses its properties and will be a weaker product than the manufacturer suggested.

but when you gell your deck the average builder like you or me is gonna roll or brush it ......the brush or roller spreads the gell thin....so thin in fact that you end up with a surface that looks more "painted" than anything......

to get the optimal "factory" look....you will need to apply it as thick as you can and use as little pressure on the roller or brush as you can. after the third coat....mix the gell "hot" let the roller leave "dimples" and let it cure. if you add aceitone or patch aid....it will start to level slightly and you will loose the "pebbeled" finish you are looking for.

you can spray the gell and get a great finish.....since the deck is not being sprayed from a mold where the pebbeled finish is in the mold.....spraying requirers a techeqnique that is kinda hard to do.......you are looking for 25 thou thick coverage.....so when spraying a deck...you want max orange peel. the orange peel is the finish.
you go really slo with the gun and build to the 25 thou.....too thick and it could crack easy....so proper speed with the gun is crucial. gellcoat spraying is allready an art....most auto painters wont touch gellcoat....so the process ive described above can be done but you would have to have lots of practise first!

when i rolled my deck it was more for waterproofing.....i will be adding snap on carpet over the gelled deck so it wasnt the pebbeled surface i was trying to attain.....

but ill tell ya....ya gotta add the non slip.......the gellcoat is like walking on ice!

cheers
oops

 

[F14CRAZY]

Re: if I wanted to gelcoat my deck...

Thanks for the tips and input on gelcoating guys. Truly it seems like the "best" deck finishing idea.

While I don't think it's out of my technical reach, I think it's out of my aesthetic appeal reach. I'm still thinking about it though...I could pick up a cheap spray gun and do a bunch of practice until I figure out how to make it look good enough to satisfy myself. It sounds like that's the challenge; not getting it to seal the deck, that's the easy part or so it seems.

I dunno. I've got some time until boating season so it definitely isn't off the table. I've been able to do a decent job at everything I've tried

 

[ondarvr]

Re: if I wanted to gelcoat my deck...

It's not hard to make it look good, the texture from the roller and sand (or whatever you use) will hide any imperfections in the glass job. You can also put a snap in carpet over it for when you want a soft surface, then you have the best of both worlds.

 

[Mark42]

Re: if I wanted to gelcoat my deck...

BTW, for anyone wanting to add snap in carpets, stainless steel snaps are available from Rochford Supply at very modest prices, about $9 for 100 pieces:

http://www.rochfordsupply.com/product_listing.asp_Q_CatID_E_411_A_SubCatID_E_454_A_ProdID_E_3459