spraying gelcoat/prep

[randy56100]

Hey guys. I got a 72 22'2 that I've been rebuilding for a little over a year. Boat is completely sanded on the outside, transom is just about done. Did a full transom with a deck. Next I would like to re gel coat the out side of the hull. Got pretty fortunate and got the gel coat from work. I'm going with a battleship gray with a black rub rail. How's the best way to go about spraying gel coat? Any input would be really appreciated. I've sprayed paint but not gel. Do I use a thinner? Sanding in between coats I know is a must but what grit and how many coats? Thanks.

[Capt. Bob]

I'm sure others will pipe in but here's a start and as always,

Search feature might be your friend.

search.php?keywords=spray+gelcoat&terms=all&author=&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

Good luck.

[fishinonthebrain]

How are you planning to spray the hull? If you can flip the hull right side up you will have some more option.

If you flip the hull you can spray the gel coat straight using a dump gun, sand and buff with really good results.  You can also use 50/50 gelcoat and duratec high gloss additive with a HVLP gun which will help thin the gelcoat out and make it laydown a lot easier like paint. Then you would need to wet sand and buff.

If you leave the hull on the trailer and try to spray it from underneath the 50/50 gel/ duratec is probably the only choice. I have not been able to spray gel in a dump gun upside down.

I chose to spray my boat with the 50/50 mix but have not had a chance to sand and buff yet. You can see the results under 1987 CCP222 rebuild thread. It has some  orange peel but is glossy and hard.

[randy56100]

The boat is hanging in my garage. I built a lift for it so I could get underneath easier and pull the trailer out.

[fishinonthebrain]

I painted my hull blocked up and I wish I could have flipped it. All the sanding and fairing would have been a lot of easier. Spraying on a flat surface is a lot easier than overhead and vertical but I did it and it came out just fine. I can't wait for the rest of the sanding and buffing on my back on a creeper.  

Just mix like 64 oz at a time 50/50 gelcoat/ duratec at no more than 70 deg and spray it with a gravity fed HVLP spray gun and it will lay down pretty smooth with a little orange peel. If it is hotter than 70-75 mix up less because the gelcoat will harden in your spray gun. Then you will spend the next 30 minutes trying to get that mess out of your gun.

[randy56100]

Since you don't use primer with gel coat, how many coats should I do and what grit sand paper in between coats? Since the gel coat is thicker does it fill pin holes and small scratches?

[fishinonthebrain]

Read page 13 of my thread 1987 aquasport 222CCP and I explained the process I used to paint my hull.

[kaptainkoz]

The dump gun works great but has it limitations as to what hand position you can effectively use it. I have an HVLP as well which I am yet to experiement with gel coat with, although i will in the spring. The thing with the HVLP is you need the 2.4 mm tip kit. Most off the shelf big box store guns come with a 1.4 or a 1.8 mm tip set up. I would think you would get more control from a HVLP but man they are a pain to clean. Spray for 10 minutes. clean for 20.