Gelcoat ?

[MUDWISER316]

What is the best way to apply gelcoat. I've tried spraying and brushing. I have not tried rolling being i'm not sure what type of roller I should use. When I spray the gelcoat it blows away and gets ripples. When I brush it on it leaves lines( maybe wrong brush type). Thanks! MUD

 

[ondarvr]

Re: Gelcoat ?

It depends on what you're trying to do. It's designed to be sprayed and that works well in most situations, using it for a nonskid surface rolling gives good results, brushing works, but like you've found, brush marks can be a problem. If you get ripples in the surface when spraying, then the air pressure is too high or you're too close, a larger tip or spray nozzle can help also. Siphon type spray guns with tips designed for automotive paint have a difficult time with gel coat.

You can also buy patchaid type products to help reduce the viscosity and get a better cure in a thin film.

 

[Bondo]

Re: Gelcoat ?

It's designed to be sprayed and that works well in most situations,

Ayuh,..... And Obviously,... You're Not using it as it's intended to be used,....
In a Mold.......

1 alternative when trying to use it as a Topcoat,... Is to lay it on Heavy,ei. Extra Coats.....
Then after it has set up,.... Sand it Smooth.......

 

[MUDWISER316]

Re: Gelcoat ?

I've been doing some repairs on the bottom of the boat being the last guy that had the boat seemed to hit alot of stuff LOL!. I have been building up the gelcoat and sanding it back down. It's just a pain in the but to judge the thickness of the coat. Thanks guy's for the inputs.

 

[Grits]

Re: Gelcoat ?

I have been through he same thing. This is what I came up with. I am gelcoat from Mini Craft. I am spraying it through an Iwata HVLP primer gun with a 1.8 mm tip. I am reducing it by about a third using their reducer. I am adding wax to the last coat. It helps to wait a few minutes between coats to let it flow out. It also helps to warm it up to seventy eight degrees. Gelcoat will not give you a finish like paint. By calling the manufacturer and following their suggestions, I have eliminated a lot of sanding.

I used an airbrush on small spots with okay results. Out of the blue, I tried an inexpensive HVLP touch up gun from Lowe's. I do not know what the tip size is but I am guessing about 1.3 mm. It worked great. I was surprised to see how well the material flowed through the small tip. Using a smaller tip may atomize the thick material better. You just have to give it more passes to get the thickness you want. With a ripply finish, your end product, after sanding, is only as thick as the thinnest spot.

The primer gun mentioned above works very well. I asked Mini Craft about a 2.3mm or 2.5mm tip and they did not recommend it. With an HVLP gun, they said you could not get enough air through it to atomize the material well with the larger tips. This is just my experience. I am an amateur. It has worked for me and I hope it is helpful to you.

Good Luck,

Grits

 

[TriadSteeler]

Re: Gelcoat ?

Grits,

What type of wax are you adding? Is it surfacing wax? I'm having trouble finding surfacing wax locally and wanted to do the same thing.