PDA

View Full Version : New to Donzis: Blistering Help??



blutegra1992
08-07-2008, 06:51 PM
Hey guys,

Just looked at a 95 Donzi 18 2+3. Boat has been left in the water every summer for quite a few years.

The stripe needs repainting and the bottom has what looks to be hundreds of little air bubbles under the white gel coat?? I guess its blistering?

How is this repairable? Extensive work? Can I do it myself? Help please.

THANKS

zelatore
08-07-2008, 07:20 PM
Blisters happen. It's not the end of the world.

First, leave it out of the water and come back and look at it again in a few days - I bet half or more of them will magically 'go away'. I'm assuming they are tiny little things - maybe the size of a pencil eraser.

There are two ways to repair them. You can grind out each individual blister, dry it, epoxy it, fair it, and paint it. That's how we do individual blisters on yachts. You could do this yourself, but you probably don't want to.

But if you've got a bunch of them, the real answer is to peel the bottom. Basically, they use something that looks like a big planer to take a thin coat off the whole bottom. Dry it out, then put on an epoxy bottom and fair it out, then paint it. This is not a DIY project - it requires specialized equipment and takes a lot of time. And it's not cheep.

But, for now, I'd just let it dry for a while and see what you've got. 95% chance they aren't causing any problems - tiny blisters like that are almost never into the laminate, only the gel, so it's usually just a cosmetic issue. If you're going to keep the boat on a trailer, you won't have to worry about them much. If you plan to keep it in the water for extended periods, then I'd look at fixing it.

Now if the blisters are bigger, say the size of a quarter or more, that's a different story. Those you need to look into fixing.

zelatore
08-07-2008, 07:23 PM
I just noticed you are looking at the boat to buy. Use the blisters as leverage for negotiation. When I wrote the note above, I was thinking it was your boat already. Have a yard quote a full peel and then throw that at the seller - it will scare him to say the least. Without seeing it and without knowing where you are and what yard rates are, I'm going to guess $4-5,000. And you do want to get some money off the price for this because should you go to sell it later, your buyer will do the same thing to you.

gcarter
08-07-2008, 07:58 PM
What Don said...
I've done a 31' FBSF and a 34' sloop. NOT for the faint of heart. But like he said, keep it out of the water , it won't be a problem.

mike o
08-07-2008, 08:24 PM
you can google it, so you can understand it, NOT good. I had a ski nautique and the bottom developed a major case , to the point that they popped when loaded on the bunks on the trailer. Mine was a fresh water boat and they never when away. They only got worse. There's been up- dated understanding on osmotic blistering. There was a big article in proffesional boat builder magazine afew years back. Its caused by the resin reversing the crosslinking because of moisture-chemicals. Thats why better boats today are built with vinylester resin which is much more chemical resistant or at least a vinylester barrier coat behind the gelcoat to prevent this. I leave my boats in the water, but i pull it out to let it dry out.

blutegra1992
08-07-2008, 08:39 PM
So the consensus is I should pass on this? It is literally covering the entire underneath of the boat, likely from sitting through the summers in the water.

?? I think I could get this boat for 8k, its a 95 everything else is in pretty good shape besides the stripe is faded. I think after I repaired all the issues I would have 13-14k in it.

gcarter
08-07-2008, 08:56 PM
They come up for sale everyday. There're plenty of them w/o any issues. Ya just gotta be patient and be ready to move when a good one comes along.
You can afford to be picky.

gcarter
08-07-2008, 09:03 PM
you can google it, so you can understand it, NOT good. I had a ski nautique and the bottom developed a major case , to the point that they popped when loaded on the bunks on the trailer. Mine was a fresh water boat and they never when away. They only got worse. There's been up- dated understanding on osmotic blistering. There was a big article in proffesional boat builder magazine afew years back. Its caused by the resin reversing the crosslinking because of moisture-chemicals. Thats why better boats today are built with vinylester resin which is much more chemical resistant or at least a vinylester barrier coat behind the gelcoat to prevent this. I leave my boats in the water, but i pull it out to let it dry out.
Mike has it in a nut shell here. The sloop I did was the worst of the two. I had the gel sand blasted off. Then I ground the entire bottom (probably 350-400 sq. ft.) to remove all the delamination. I built up the really bad areas (the worst areas were delaminated probably 1/2 way through the hull) sealed the entire bottom w/epoxy, filled and then faired the bottom w/thickened epoxy, and then sanded smooth. since the bottom was now epoxy, it had to be primered and painted. And kept painted.

blutegra1992
08-07-2008, 09:20 PM
Yikes... well thanks for the replies.. I am gonna steer clear of this one. Too bad... I liked it.

harbormaster
08-07-2008, 09:26 PM
August and Sept are the good months to boat shop. Alot of folks are trying to dump their boat before they have to put it away for the winter. I had a 1995 18 Classic that I paid 10.5 for in 2000. Be patient and have cash ready.

ky-donzi
08-07-2008, 09:42 PM
There are a couple nice ones on ebay right now. It never fails, I bought mine last summer and it seemed that there was a shortage of Donzi classics out there, and I have seen alot this summer for sale.

Watch ebay and boat trader.

mike o
08-08-2008, 08:01 AM
Actually, I think my first post was asking if my 95 sweet 16 was made with vinylester resin.........

The Hedgehog
08-08-2008, 08:21 AM
I doubt it.

I don't think that they went to vinylester until way after 97