My Donzi is beat...

[superhatz]

As some may remember, I bought a very original 1970 18 2+3 awhile back. Well...last week, I finally got around to putting the boat on stands and planed on wet sanding and buffing the gelcoat...and repairing some chips and dings...blisters...trying to maintain the most originality I can. I don't mind a little "patina".

Anyway...my boat is very original but in much worse shape than I thought. Don't get me wrong..It's still my "dream" 18, but I don't really need more $hit to fix...I'm not giving up.

The hull has "pox" (many small blisters) and a lot of stress cracks on the gel. The cracks extend up the sides...which is original black gel...with an Inca Gold stripe.

Double anyway...I'd like to repair the gel as best as possible to maintain originality. The boat will always be trailered and kept in my garage. I'm aware paint would be easier but I'd like some advice in repairing the gel...the cracks worry me a bit....they are very long. Do I need to re-gel the whole hull?...grind it all off?

Long winded thanks!

-Aaron

[gcarter]

Do I need to re-gel the whole hull?...grind it all off?

-Aaron

Yes.
They (the tool companies) make hand planers thet will remove the gel in about 4" wide strips. Other alternatives would be to blast it off, or grind it. The osmotic blisters will have to be completely removed, even if it continues below the glass surface under the gel.
Let me tell you Aaron, it is a lot of fun to fair the new gel after you've taken the old gel off.
I won't be the one to tell you there mey be other opportunities out there.

[superhatz]

Thanks George....so you're saying making spot repairs to the hull would be worth it?...just grinding out each blemish and filling? The hull still "sounds" okay...doesn't seem to be delaminating?

[gcarter]

You can grind out the cracks, but all the little blisters (on the bottom, right?), well, all that gel has to come off.

You can grind out the cracks, over fill them w/polyester putty, then sand the surface fair, then re-gel.

[superhatz]

George...you are a total buzz-kill....

Thanks!

[mrfixxall]

what george said!

their is a easy way to do it,,
have the bottom soda blasted,fix the cracks bt grinding them out then flare it out then fill with vinyl ester resin and woven mat,grind it out again and fill with durates vynelester fairing putty..you can use the duratec on the blisters also..after filling the repairs get a long board and block the whole bottom with 80 grit then follow with 120..after you have the whole bottom blocked out..

if the bottom of your boat is straight you could also use duratec's vinylester fairing primer to fill the blisters http://www.duratec1.com/dp16.html
but i like to use the putty because i can control the thickness and not waste as much material..after you have the cracks repaired and the blisters filled i would use the duratech clear gel additive and mix it 1to1 with the gel coat your going to use http://www.fibreglast.com/product/910/Gel_Coats
with this additive you can spray it on like car paint and dont have to worry about adding wax to the gel so it can cure..you will have to apply more coats the gel and wax but if you use the duratec the finish comes out much better and you will have less sanding when you go to wet sand and buff it..

[superhatz]

Thanks fixall...that helps quite a bit.

New question?...is the original Donzi white gel a standard white?...can I buy some? Black and Inca Gold too..I guess?

Thanks!

[mrfixxall]

Thanks fixall...that helps quite a bit.

New question?...is the original Donzi white gel a standard white?...can I buy some? Black and Inca Gold too..I guess?

Thanks!

you can cll minicraft but their expensive or try ferro corp,574-935-2131 x2532 ask karen if your color is available,she will send you some color chips and just buff out a spot that is still good on the boat and match it up..

[gcarter]

The main problem w/the blisters is that they can extend into the glass substrate. They originate from leaving the boat in the water too long and osmotic action actually draws the water through the gel and into the glass. Once under the gel, the water can have some undesirable reaction w/some of the resin by-products and can seriously effect the integrity of the glass. That's why it's important to grind (or blast, I've done it both ways) out the blisters to determine the depth of the problem. More than likely, the damage runs to just below the gel.......but you have to find out.
Aaron, no kidding, this a BIG project. It's not for the faint of heart.
Mike has a lot more experience than I do, particularly w/the various products available, as he does this for a living and I'm just a hobbyist.
As far as the white color goes, Minicraft told me that many boats in the '70's and early '80's used "Classic White" which seems to be somewhat of an industry standard. If you're doing the whole thing over, anything close will work. There must be 50,000 different shades of white.

[mike o]

Old back issue of professional boat building covered it well. Its still available from PBB.. A lot of chemistry, seems the resin behind the gell reverses the cured reaction and starts to to gas off, like it did when it originally curing. Can find my old issue. type in osmotic blistering in the search box , issue #15,......http://pbb.proboat.com/index.php. Fix is a total vinyl ester barrier or inter protect type stuff, behind the gells substrate..... I have a friend with a 2 yr old 60k high end ski boat. Its got "it" bad, gel not covered under warranty, so their telling him......

[mrfixxall]

The main problem w/the blisters is that they can extend into the glass substrate. They originate from leaving the boat in the water too long and osmotic action actually draws the water through the gel and into the glass. Once under the gel, the water can have some undesirable reaction w/some of the resin by-products and can seriously effect the integrity of the glass. That's why it's important to grind (or blast, I've done it both ways) out the blisters to determine the depth of the problem. More than likely, the damage runs to just below the gel.......but you have to find out.
Aaron, no kidding, this a BIG project. It's not for the faint of heart.
Mike has a lot more experience than I do, particularly w/the various products available, as he does this for a living and I'm just a hobbyist.
As far as the white color goes, Minicraft told me that many boats in the '70's and early '80's used "Classic White" which seems to be somewhat of an industry standard. If you're doing the whole thing over, anything close will work. There must be 50,000 different shades of white.

All of what George stated is true,,you will nee a moisture meter to find out for sure if all the water is gone after the bottom of the boat is striped or blasted, if moisture is present your boat will need to sit in a dry garage with dehumidifiers and heat applied to the hulls bottom in order to make the correct repair..i have done thease repairs in my younger years but now i try to stay away from it because of all the time and effort really didn't pay off so now i try to stick to the mechanical aspect of boats..

[superhatz]

Thanks for the help guys. Unfortunately, I get very attached to things and probably won't give up on this one. I love the originality and color combo...290hp H&M is cool too....

I'll probably redo the hull at some point...but not this year. I'll keep you posted...

[mrfixxall]

Thanks for the help guys. Unfortunately, I get very attached to things and probably won't give up on this one. I love the originality and color combo...290hp H&M is cool too....

I'll probably redo the hull at some point...but not this year. I'll keep you posted...

Holy Chit!!! all those bumps will have to be opened up! you will nees to strip the old gel off and start from scratch.. you can use a counter sink bit to open them up..follow this video so you can have a idea on what you are getting into..

[media]http://www.youtube.com/watch?v=b0XBPbXKz8s[/media]

[superhatz]

Yeah...like I said..."beat"...

Thanks man...

[The Hedgehog]

Fixx and G are dead on. Your best bet is to find someone that planes gelcoat. That is way too much for the old pop and grind. Figure around $2k to strip that bottom. You may be able to get it done for less but it is kind of like painting. If you watch someone that is good with a gun or planer you will think you are getting ripped off. If you don't have experience and try it yourself.....ouch.

Listen to these guys carefully. It needs to be good and dry before anything goes back on.