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tmdog
07-19-2002, 03:51 PM
Bought a 88 Donzi in Fl. several years back.After sitting in the Ga. sun the coating started to peel.Later I realized the rascal in Fl. probably had the boat clear-coated. Took a pressure cleaner to it, blew 95% of the coating off it. Now left with a badly oxidized surface. How can I get the gel coat back to normal, if that is possible? Color, white w/ red stripe.

Rich
07-19-2002, 08:11 PM
tmdog.....
Get out that sandpaper starting with 320 grit. Wet sand 'er smooth.
Go to 400 grit and wet sand 'er smoother
Go to 500 grit and wet sand 'er even smoother
Then......600 grit and wet sand 'er the smoothest
Buff it out with a good polishing compound
Wax 'er
Seal 'er
Your done.......
Til next year.....

Keep up with the waxin' and sealin' and you shouldn't have to sand again......
P.S.
In between all the sentences above........add
Have a beer

Pacinda
07-20-2002, 05:39 PM
I wanted to ask the same thing for my boat. Thanks to everyone for the help.
Thanks Mark

tmdog
07-20-2002, 06:25 PM
Thanks Rich P. I had a huch sanding was involved. Will give it a try since I want the Donzi to look good. Thanks again.

MOP
07-23-2002, 06:40 PM
Renewing the clear coat is not a bad idea, my gel coat is really nice but some of the places I go gets my boat really brown. I trailer so I acid bath it and rewax for now. But my friends that have clear coat or clear Awlgrip even better on their boats stay clean and hose off. I did learn a trick for getting it in the water at dirty ramps and still look good. I spray the sides and most of the bottom with liquid soap, most anything cheap at the discount house of worship the muck just falls off.

Ranman
07-23-2002, 07:05 PM
Isn't 320 a bit rough? Heck, isn't 600 a bit rough? I thought you'd wet sand with 1000 or 1200. I used 1000 on a Mustang once and it didn't take much to reach the primer. Wouldn't a little compound being very ginger with a wheel would do it.

Scott P, You're the pro. What do we all do about the oxidization on our Classics?

HyperDonzi
07-23-2002, 09:43 PM
would clear coating a boat keep the sun from fading the gelcoat?

David Ochs
07-23-2002, 11:34 PM
You really shouldn't use sand paper to remove oxidation. Would you use a brillo pad to clean your windows? If you still have some of the clear left on there, please go light with 1200-1500, even 2000 if you can get away with it. Otherwise use only a fine polish, my favorite is 3-M "finesse-it" which you can use with a waffle foam buffer pad.

MOP
07-24-2002, 03:09 AM
You will be surprised at how deep the dead gel coat goes, gel coat is alot thicker than paint and alot more porous than most people realize. Wet sanding is the quickest and to me the best way to ge the color back. I start with 400 just till I start to get color (still a little dull left) then switch to 600 till color gets pretty bright then 1000 during the whole process us a goodly amount of water either lightly running from a hose or frequently changed. Then its dicision time. You can go with a good quality wax but in a few years you will be doing it again and that can be touchy depending on how bad it was the first time. If you want very good protection and durability spend the extra bucks and clear Awlgrip it. Its not the product cost its getting a real prop to shoot it. It is a common practice on mega yachts in southern waters to coat the varnished wood it lasts many years. The idea of clear coating has been around for a long time it is the only way to seal the surface. Use any good clear coat wax afterwards, it will be worth the effort.

Rich
07-25-2002, 07:55 AM
I wrote my reply based on reading everything I could find on gelcoat, talking with different shops & gelcoat manufacturers. Then I experimented with the gelcoat on my badly oxidized 66 2plus3. I got the best results with the method I first described which was told to me by a guy thats been restoring fiberglass boats for many years. Since tmdog said the clear coat was mostly removed I didn't consider trying to fix that. No matter how fine you go with wet sanding, a final buffout will be required to get a scratch free mirror like surface. I wet sanded using 1500 grit and still had to buff it out. Saw no difference after buffing when 600 grit was the finest grit. Since gelcoat is usually about twenty thousands thick there is some breathing room for error. Be especially carefull at the edges (outside corners). You may want to use only the 600 grit there. And then you still have to easy with the buffer.

rong
07-25-2002, 08:10 AM
Hey Dave, I like the 3M "Finesse-it II" also! It is the final before waxing etc. I use the super-buff pad. This product gets the gel so smooth you'd be tempted to leave it alone. It makes waxing extremely easy. It's also capable of removing light to medium oxidation. I got to believe it does alot for sealing as it extents the time between buffs.

Greg Maier
07-25-2002, 09:23 AM
What kind of buffers do you use for gelcoat, orbital or high speed?

Donzigo
07-25-2002, 09:30 AM
PORTER CABLE tools are the only ones I buy, now. There are many good tools out there; but, the Porter Cable factory shop is in tampa on Kennedy blvd and they have great prices on refurbished fully warranteed tools for ridiculous prices. For buffing, get a large Porter Cable buffer that has variable speed. Probably will cost you about $130. But, at $12 to $15 per foot to have someone else do it, youare better off to buy the tools and do it yourself. Don't kid yourslef by buying those Sears or Discount Auto foo-foo buffers. Buffing a boat is a job for a real buffer.

HyperDonzi
07-25-2002, 10:53 AM
gelcoat is around 1/64 of an inch deep if i remember correctly.

cheezhead
02-27-2004, 08:04 AM
gelcoat is around 1/64 of an inch deep if i remember correctly.

That's assuming the boat is new and has been kept up with wax. Every time you buff your boat, you are thinning out your gel. Salt and use affect the gel, as well. Salt is abrasive and rubs constantly on the hull. Therefore, you can't assume that you have enough gelcoat to sand (or even compound in severe instances). I would certainly recommend trying to compound and buff before wet-sanding.

Fish boy
02-27-2004, 08:46 AM
My borther and I bought a testarosa 18 in the early 90's that had been sitting in a auction yard outside for over 2 years. The beautiful red deck was almost white with a pink tint from oxidation.

I wet sanded starting with 600 (by hand, NOT a grinder, buffer,...etc), not beleiveing that it would do any good, but figured I could not hurt it. After a couple of weeks of sanding (600 then going progressively higher), then compounding, then polishing, waxing, and eventuyally buffing, the gelcoat looked so good that even when it was dry, it looked like there was a coat of water over the deck. Boat was even in a local newspaper it looked so good. Really wish we would have kept it :(

Fish

DOND
02-27-2004, 03:36 PM
My red 1969 16 was so badly oxidized it was almost pink. The boat had sat in fresh water for along time that it developed a scum line just below the boot stripe that it had turned the gel almost white. I sanded those areas with 320 and some 240. The rest was started with 400.Once the oxidation was removed I sanded with 600,1000 and then 1200.I used Malco cutting creme when buffing. This seemed to polish out the sanding scratches very well and brought the finish to a high gloss much better than 3m super-duty.Once the oxidation is removed the different grades of paper eliminate the scratches from the coarser grits.I then polished with a glaze and then sealed with paste collinite.It turned out great people cannot believe that it is the same boat.
The gel on those old classics are very thick, I used a micrometer to measure the thickness on some loose chips I removed from my deck and recorded anywhere from .035-.040.
Don

florida gator
02-27-2004, 07:47 PM
3m fast cut made mine look great. Follow it up with waxand I cann't imagine it not getting the job done. BTW that was reccomended by a friend whohas a body shop that I went to for an estimate on new gel coat. He couldn't take my money and made the reccomendation.

JimG
02-27-2004, 08:59 PM
Results are as shown...

I used 220 on a orbital sander, then 400, then 600, then 1000, then 2000. (Believe me, I tried it backwards first...) After that I used a heavy compound then cleaner wax. Next Collinite.

Look closely at the pic. This was while I was testing the method. Everything under the decals was done as described above. Look at the difference in color. Never went through anywhere. LOTS of gelcoat on these older boats.

Jerry Eisele
02-28-2004, 06:31 AM
I've had great results using 2000 wet, a gritty compound, Eager- Buff 600 and a good sealant. The key is to seal the gel coat, or you will loss your shine. I spent four week ends on our Carver last spring and it still had a super shine in the fall. My Two cents worth??

smokediver
02-28-2004, 08:58 PM
I usually wet the surface first to see how it looks. If it is nice and glossy you can get it to look that way dry with elbow grease. Unless you have deep scratches, stay away from the heavier grits. Depending on the size of the swirls and scratches. I always finish up with 2000 or 2500 w/d paper. Remember, what makes a high gloss is a smooth surface ie tiny scratches. I havent come across a compound yet that removes 1000 sand scratches that doesnt create deep swirls. after the 2000 try 3m part # 5933,perfect 3 rubbing compound, with a white waffle pad. after that switch to a black waffle pad and use machine glaze. I like the perfect-it 2 machine glaze more than the perfect it 3. I work mainly on dark hulls and it seems the perfect it 3 machine glaze loads up the pad too much. after the glaze, a good ole carnuba wax. when it is all done , go over it with a good micro fiber detailing cloth to remove the wax streaks ..

knee deep
02-29-2004, 04:58 AM
I re-gel coated the '68 18 2+3 and we started with 320 wet and went all the way to 1200 and then used Aqua Buff 2000. The boat shines like the proverbial mirror. I love Finesse It but there is a new and better product from 3m called perfect it and it has a specific waffle pad and does a fantastic job.

Depending on how bad it is I'd try some course compound, possibly even the brown stuff from 3m with a high speed buffer and see what it does. If the results aren't good enough go back to 320 and sand, sand, sand, sand, sand.

I only used the Aqua Buff on the 18 because thats what the guy that mixed my gelcoat said to use and we did get one helluva mirror finish.

As stated earlier be very very careful at corner and at the chine and strakes as the gel can be a little thinner in those places.

Believe me it sure beats repainting.........

FISHIN SUCKS
02-29-2004, 01:34 PM
I used a 'gritty compound' that I wiped on, buffed off. The red on mine was turning to a white-cream puke color. I found this stuff through a an old time boat builder, fiberglass repair guy just up the road here in IN. He suggested I use the compound before sanding. Sure enough, it really worked. I'll find out the name tomorrow and let you know. This sure beat the hell out of sanding, just don't know if you gelcoat is too far gone.

FISHIN SUCKS
03-03-2004, 08:30 PM
Okay, here's the name of this 'gritty compound' I used and totally amazed me: T. R. 311 super duty buffing compound, by TR Industries located in Southgate, CA, 213-923-0838. The guy at the fiberglass shop said it doesn't take much and he was right. He poured some out of a one gallon jug and was enough to do the 'bubble deck' and both sides. I used a grinder type buffer with a terry-cloth pad to work it in, then used a lambs-wool pad to buff it out. I did it a second time on the bubble to even out some spots that I missed. Then use a nice polish (I used maguires). This did an excellent job, and beats the hell out of sanding!