What gel to use? What cleaners, etc?

I have a 20' Kona that was originally brown metal flake (yuk) that someone sprayed automotive paint over. The auto paint looks like hell and I would like to gel the boat while the engine is out.
Now, I've done a lot or car painting, aircraft fiberglass repair but I have never messed with gelcoat. I assume that I'll need to sand through the paint into the gel, clean and apply new gelcoat with no clear coat then buff and wax 2 weeks after???
*Can I gel over the paint if it's feathered good?
*What grit should I use to texture the surface before spraying gel?
*What type of cleaner to use?
*What brand of gelcoat is easy to work with, reasonably priced and is durable?
*What would I expect to pay for enough gel to do a 20' semi-daycruiser w/ closed bow?
*Special spray gun to apply gel? Gravity? Siphon? Nozzle size? Air pressure? How many coats? Will it thin enough to use in an airbrush?
-Chuck- Oregon

I would spray it with a good polyurethane paint. The worst part of gel is the sanding and sanding to get the gel smooth enough to polish. If your set on gelcoat, you can sand down with 120 and spray. You will need to thin the gel out with duratec to spray. I would stick with paint. Gelcoating a whole boat is very labour intensive.

Hmm, I just didn't think it would hold up well to people walking on it, etc.

well I have recently been trying my hand at spraying some gel. I have had very good success. I just purchased a boat with major stress cracks around cleats etc. I ground them out, filled in the grind marks then sprayed with gel. I also fixed a place on my last boat where a guy dropped the anchor on the bow. It took a hunk out that was probably 3 inches wide. Same thing was done. I ground out the bad gel. Filled in the low spots then sprayed gel. Now I havent tried spraying anything the size of an entire boat but if you have the tools I think it can be done with no more trouble than auto paint.
With auto paint you have alot of prep work to get a good final outcome. With gel its the opposite. You sand it down with something like 120 then spray the heck out of it. then you must go back and wetsand until smooth then buff. Either way you work in the beginning or the end.
I have not tried this but I would think you could spray a boat in sections. Possibly spray a side, then another then finally the top deck. Gel seems to blend seamlessly while auto paint is a pain to blend. I dont see why you could not break the work up in stages which would make things alot simpler.
Do some research. There is an additive out now that you add to gel to make it more spray friendly. Its supposed to flow out more like auto paint. I have not used it I have only used a typical hvly paint gun but I havent had the first bit of trouble.
If your going to try and entire boat or a large section requiring multiple fillups. I would make sure you have 2 guns and a guy who can mix and clean the gun while you are spraying. This stuff is not like paint. If it sets in the gun that gun is toast. you might get a max of 5 min spray time before its gonna start getting thick.

I have a 20' Kona that was originally brown metal flake (yuk) that someone sprayed automotive paint over. The auto paint looks like hell and I would like to gel the boat while the engine is out.
Now, I've done a lot or car painting, aircraft fiberglass repair but I have never messed with gelcoat. I assume that I'll need to sand through the paint into the gel, clean and apply new gelcoat with no clear coat then buff and wax 2 weeks after???
*Can I gel over the paint if it's feathered good?
*What grit should I use to texture the surface before spraying gel?
*What type of cleaner to use?
*What brand of gelcoat is easy to work with, reasonably priced and is durable?
*What would I expect to pay for enough gel to do a 20' semi-daycruiser w/ closed bow?
*Special spray gun to apply gel? Gravity? Siphon? Nozzle size? Air pressure? How many coats? Will it thin enough to use in an airbrush?
-Chuck- Oregon
#1, Do not attempt to gel over the paint. It will bite you in the ass later. If you are set on using gelcoat, the paint must be completely removed.
#2, Gelcoat can be sprayed over some pretty rough scratches. Anywhere in the 80-220 range will be fine.
#3,Gelcoat is very porous and may tend to absorb the cleaning chemicals. I would suggest an alcohol based wax & grease remover such as PPG's DX394 as a final clean before spraying. For general cleaning, acetone.
#4, I use Valspar's products here, but their products are designed for the industrial market are not typically user friendly. For the do-it-yourselfer, I recommend contacting Mini-Craft at (352) 748-5200.
#5, Single color, about 2.5-3 gallons if you aren't doing the bottom. 5-6 if you are. Last time I bought gel, white was over $70 for a one gallon, but I could get a 5 gallon pail for about $160. Black was just a little more. I don't generally buy large quantities of colors, but blues, yellows, and especially reds can be close to double those prices.
#6, I would suggest a gravity feed, HVLP type gun with a 2.0-2.2mm tip. Air pressure depends on how much you thin your gel. If you only want to do the job once, go for 30-40mils thickness, in 3 coats, because you are going to sand half of it off. I usually spray 2 good coats with just gelcoat, styrene monomer and catalyst, then add patch reducer and a little surfacing agent to my last coat. Pretty easy if you are doing a solid color but if you have to pull tape lines you have to work fast. You probably could thin gel enough to spray from an air brush, but it wouldn't cover worth a damn. I wouldn't suggest it....
Fibre Glast Developments (www.fibreglast.com) offers a gravity feed gun with a 2.5mm tip (p/n 126-a). Hope this helps...Good Luck!

#1, Do not attempt to gel over the paint. It will bite you in the ass later. If you are set on using gelcoat, the paint must be completely removed.
#2, Gelcoat can be sprayed over some pretty rough scratches. Anywhere in the 80-220 range will be fine.
#3,Gelcoat is very porous and may tend to absorb the cleaning chemicals. I would suggest an alcohol based wax & grease remover such as PPG's DX394 as a final clean before spraying. For general cleaning, acetone.
#4, I use Valspar's products here, but their products are designed for the industrial market are not typically user friendly. For the do-it-yourselfer, I recommend contacting Mini-Craft at (352) 748-5200.
#5, Single color, about 2.5-3 gallons if you aren't doing the bottom. 5-6 if you are. Last time I bought gel, white was over $70 for a one gallon, but I could get a 5 gallon pail for about $160. Black was just a little more. I don't generally buy large quantities of colors, but blues, yellows, and especially reds can be close to double those prices.
#6, I would suggest a gravity feed, HVLP type gun with a 2.0-2.2mm tip. Air pressure depends on how much you thin your gel. If you only want to do the job once, go for 30-40mils thickness, in 3 coats, because you are going to sand half of it off. I usually spray 2 good coats with just gelcoat, styrene monomer and catalyst, then add patch reducer and a little surfacing agent to my last coat. Pretty easy if you are doing a solid color but if you have to pull tape lines you have to work fast. You probably could thin gel enough to spray from an air brush, but it wouldn't cover worth a damn. I wouldn't suggest it....
Fibre Glast Developments (www.fibreglast.com) offers a gravity feed gun with a 2.5mm tip (p/n 126-a). Hope this helps...Good Luck!
So Ducky, do you recommend polyurethane to the do-it-your-selfer?
Greg

has anyone used the gun specifically for gel coat that fiberglast sells. Its the one which uses the paper cups so cleaning the gun is easier.
thanks

has anyone used the gun specifically for gel coat that fiberglast sells. Its the one which uses the paper cups so cleaning the gun is easier.
thanks
Are you going to be doing a lot of gel-coat work in the future?

Are you going to be doing a lot of gel-coat work in the future?
possibly. Ive thought about regeling an entire boat plus making some custom race hatches etc.

So Ducky, do you recommend polyurethane to the do-it-your-selfer?
Greg
A quality polyurethane is most certainly easier for the average person to use, and obtain. If a boat has already been painted, then absolutely. But I hate to see someone spray paint over a boats original gelcoat.
Anyways, that gun that your guys are referring to with the paper cups is called a "dump gun". It has no needle and is supplied with a 3/16" orifice. It is for manufacturing parts, not for spraying parts outside of the mold. It moves waaaaaaaay too much material for an external spray job.

Anyways, that gun that your guys are referring to with the paper cups is called a "dump gun". It has no needle and is supplied with a 3/16" orifice. It is for manufacturing parts, not for spraying parts outside of the mold. It moves waaaaaaaay too much material for an external spray job.
gotcha. ill stick with my $8.00 harbor frieght throw away guns.

Nothing wrong with those if they have a sufficient tip size.

A quality polyurethane is most certainly easier for the average person to use, and obtain. If a boat has already been painted, then absolutely. But I hate to see someone spray paint over a boats original gelcoat.
Well, the wife hates the color of our Miller so I've got to make the change to keep her happy and me being allowed to spend what I need or want to. :) Besides she's got an idea that she wants for the paint job... Whew, I'm going to have to some art work for that to happen. That's been a long time.
Anyways, that gun that your guys are referring to with the paper cups is called a "dump gun". It has no needle and is supplied with a 3/16" orifice. It is for manufacturing parts, not for spraying parts outside of the mold. It moves waaaaaaaay too much material for an external spray job.
Not me, I'm just going to paint. No mold making for me. Thanks, Greg

Nothing wrong with those if they have a sufficient tip size.
I hate that store.... I spend too much money when I go in there. :D