5 coats of bottom paint and it's not budging

[exudedude]

I have to much to sand off and it is not in the budget to get her blasted this yr. Is there a bottom paint I can just roll on over the old bottom paint. There is enough existing millage to where I could sand out the rough spots. I keep the boat on a lift so it really does not matter if it is anti-fouling or not. I'm looking for something nice and easy.

TIA!

 

[DennisG01]

What's your ultimate goal with the bottom? Reading through what you wrote, it sounds like you're not concerned with needing it for anti-growth. Why not just let it alone and let it wear down naturally? FYI, paint stripper works well.

What type of paint is on there, now?

 

[Fishtales]

Is it ablative or hard paint?
If ablative, leave it alone. If hard, you have a choice leave alone since on a rack or put ablative (a different color) over it.

 

[fishbust]

As long as you do not have moon craters, you can leave it alone. If moon cratered, it will rob you of performance and suck down the fuel.

 

[exudedude]

I have re-evaluated the whole thing. The pneumatic DA did not do hardly anything to it. I got a 6" peel and stick disk and put it in my drill and it is chewing it off pretty well with 100 grit. I am only going to do the transom and the hull side. I will then go over it with 320 and then I was planning on wet sanding the whole hull with 800 grit. I will then compound, wax and polish out the boat. The very bottom can wear off naturally. I will sand out any bad craters.

 

[ROBERTH]

Some DA's will lock and use like a grinder and remove material very fast. Have to be careful.
I used DA orbital air sander on mine which was very thick and cratered. Started off with 24 grit which removed it pretty quickly. Worked it until I could begin to see through it, then moved to 80 grit and removed more, but not all the bottom paint. Then moved to 150 and at this point, I re-gelcoated. But if former person that grinded did not take too much gelcoat off the first time, I could have likely just sanded progressively and polished it out.
Not a fun job, but the 24 grit took it down pretty quick.
I tried a couple of strippers and yeah, they work, but was very slow and I was more wet than the boat when trying to pressure wash it off. In the end, was better for me to just suit up and lay down and use the sander.

 

[exudedude]

I don't think I will burn through, I'm used to sanding out fine antiques. Gelcoat is something out of my element though. If I needed to touch up the gelcoat do I have to tahe it all the way to the glass or can I mist over the existing like you can laquer?

Thanks!

 

[onoahimahi]

I use my woodworking 5-inch sander attached to a shopvac. This is the kind with 8 holes in the paper. Since the hull is so flat, the suction from shopvac pulls the sander to the work so all I needed to do was guide it along. The shopvac collects all the dust. My boat wasn't too bad so I just used 60 grit.

http://www.amazon.com/DEWALT-D26451-5-I ... der+dewalt

 

[exudedude]

Well I thought wrong I did burn through on 3 spots. 2 the size of a quarter and one the size of a dime.

Can I just rough up the spot, clean with acetone and "spackle" some on with a putty knife or does it have to be sprayed? What is a good spray gun for gelcoat anyway? I know about the preval, but I mean for larger jobs?

 

[ROBERTH]

When I did the sanding, I figured that I was really getting thin on the gelcoat layer, so that is another reason I chose to rebuild the thickness for protection. However, if you want to just touch up some spots, the Preval works great. Just spray out the spots and then after cure, sand smooth and polish and you will not know it was there.

Lots of reading on THT about gel coat and lots of experts as well. For me, and my background painting auto/industrial for years including Imron's and Acyrlic Urethanes, I had a old Eclipse 78 spray gun that I used. I sprayed cars with same gun and it came out with excellent results and no orange peel, but the gun could also handle the heavy urethanes.
So I have been using it with the Gelcoat as well but using Duratec to help is spray better. At times, I have used Styrene to reduce it some, but not much.
In the end, you will get some orange peel affect depending upon spray method, reduction and how heavy you apply it. To get it smooth and pretty, you just sand progressively usually starting with 240, 320, 400, 600, 800, 1000, 1200, 1500, 2000 wet and then polish it. For the bottom, I skipped most of the grits. Started with 320, then I think 400, 800 and then polished it. But I keep getting areas that start to show the sand scratches and have to repolish it. I have been too lazy and haven't had the time to get out the air jitterbug and 2000 to resand and then polish. I just hit it again with heavy cut and it comes to life in seconds. Eventually, once per year if I keep hitting it like this, I might not have to do the 2000 wet. :mrgreen: But again, it is the bottom and it is smooth and nice! Much better than the old hard bottom paint that was chunky.