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restoring gelcoat - Need Help

6K views 12 replies 11 participants last post by  labatt 
#1 ·
I have a 1978 PSC25. The previous owner has taken all of the hardware off the boat in preparation to paint the entire boat. I am debating the merits of this plan and looking at the the pros and cons of a painted boat. The orginal gelcoat is chalked and faded but appears to be in good condition. My understanding is that PSC gelcoats are quite thick and there might be some "room" to restore the gelcoat to its original shine. The owner of another PSC25 "Intregity" (photos on the PSC25 yahoo group website) restored his gelcoat by wetsanding the topsides, deck and cabin with both a power sander and by hand. He worked his way through grits 400, 600, 800, 1,000, 1,200 and 1,500 followed by compound, polishing and wax.

It would appear that the results on Integrity were great. Before I begin sanding away can anyone comment on this approach? I don't want to damage it. I understand that I need to take my sanding slow and could easily sand through the gelcoat. In general thought is the approach taken by the former owner of Integrity common and a good plan? I haven't found much on the web or in books about restoring a gelcoat. Any tips on how much to sanding I should do as I work my way through levels of sandpaper?

As for painting - if the gelcoat is in decent shape and restorable, why would someone want to paint a boat? (Except for the obvious reason of wanting a new color.) Is this asking for further maintenance in the future as the paint fades or wears away?

Many thanks!
 
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#7 ·
Sometimes the jell coat is just to far gone. You might bring a shine to it, however it may not last. With in a few weeks of sun and water the boat looks pretty much like it did before all the work you put into wet sanding buffing and polishing and waxing. A good paint job done right with a quality Linear polyurethane in the long run will be cost effective in the long run. Once applied your only maintenance will be to hose it off and scrub it down ever so often. if the work is done properly it should last for years.
 
#8 · (Edited)
The absolute last thing you should do with gelcoat is to paint it. There is NO boat paint on this planet that will withstand the rigors of a 'boating environment' as well as simple gelcoat.

Gelcoat is usually quite thick, in most cases easily restored back to 'showroom conditions' ... and even if your restoration so 'thins' by agressive sanding/polishing the gel, you can easily spray new (and colormatched) gel over the old.

First get a pocket low power microscope and look at the condition of the gelcoat. When look at the gel under the microscope ... what you dont want to see is something that looks like a dried out pond .... little cracks looking like the back of an alligator. If thats the case, the gel is gone over the the darkside and cant be buffed/sanded and must be entirely removed and gel resprayed .... in this case you apply a barrier epoxy primer and then and PAINT the boat. If the gel under the microscope looks reasonably intact (no microcracks) then you can sand away with extremely fine wet/dry paper (600 ---> 1000 ----> 1300 ----> 2000 grit) over a rubber sanding block until you have a FLAT surface. Keep the paper wet when sanding and use a few drops of dishwashing detergent to 'lubricate' the paper and to keep it from clogging with removed gel. You can add gelcoat patch to the gouges, large cracks, etc. before sanding down; you can have the repair gelcoat computer matched to the exact color of your hull topsides, etc. .... just do a websearch for the suppliers and methods.

Once carefully flat-sanded down, then use a variable high speed autobodyshop polisher and 'knobby foam rubber' polishing bonnets. If you sanded as above you can 'start' buffing-out with 3M Finese-it (about 1300 grit compound) .... Buff out in 2ft. by 2ft. squares until you complete the whole boat surface to be buffed. Keep the buffing pad 'moving' across the surface so you dont burn the gel; be escpecially careful around edges and corners as they rapidily can be buffed through to the FGR matting layer.
Repeat the buffing on the areas that dont return to a 'decent' shine.

Then repeat the buffing-out using a new knobby foam rubber polishing pad and 3M "Perfect-it" polishing compound (probably @ 2000-3000 grit). At this point in the restoration process the surface should look like the day that the boat was in the showroom.

Finish by waxing the surface ..... but in a special way to insure that wax get INTO the pores of the gel and so that it doesnt begin to oxidize all over again. WET your BARE hand, rub on some natural Brazilian CARNAUBA (Collenite Fleetwax, etc.) and PUSH the wax into the surface, keep rubbing and pushing until the wax disappears and the 2x2 area gleams, then wax again using a very small amount of wax until the surface gleams, apply a 'dime size' amount of wax to you hand and smear it all over the 2x2, let partly dry and then BUFF with a clean knobby pad at moderately high speed.
Continue in 2x2ft. squares until the boat 'dazzles' like it did when it was band new.
Finalize (remove wax streakes, etc.) using a wet bare hand, a teeny bit of wax .... and wipe it clean with a MICROFIBER polishing cloth.

BTW this is the way a boat is buffed-out when its pulled from its mold !!!!!!

If you have small areas that after buffing that have become 'thin' and you can see the color/patterns of underlayment throgh the gel, then do websearch for "gelcoat spraying" + repair. You can buy selfcontained spray bottles (PreVal Spray bottles) with which to spray on the gel and the 'finishing chemicals that are sprayed on top of the fresh gel, etc.)

Dont paint your bout unless its absolutely necessary. Its easy (but a time consuming job) to restore just about any gelcoat back to the original shine. Original gelcoat is quite thick ... up to 3/32" thick .... dont be afraid to buff out gelcoat. Even if you burn-through or sand too deep, gelcoat repair is fairly easy (if you arent a klutz).

Id also avoid the "acrylic coatings" such as "Island Girl", etc. as they ultimately need to be entirely removed and if you dont your boat will look like it has a skin disease until you do remove it.

:)
 
#9 ·
Okay... total tangent here. Crosswalks are painted with what I think is an epoxy impregnated with glass beads or aluminum oxide. Same with metro bus floors ,a hard paint and aluminum oxide. Why not boat decks? It is nonskid, easy to clean, ostensibly sticks to anything, and looks essentially the same as gelcoat. Is anyone familiar with this material?
 
#12 ·
There are many many boats that are 20. 30, or more years old with the original gelcoat in good shape through only minimal care over the years. I agree paint is a last resort - only if the gelcoat isn't restorable. A good two part LP paint should last 7-8 yrs - then paint again.
Brian
 
#13 ·
By the way - we followed Maine Sail's newer process (http://www.sailnet.com/forums/gear-maintenance/52772-tips-compound-polish-wax.html) and used the Presta Gelcoat Compound, Presta Ultra Cutting Creme, and the Fleet Wax Paste along with all of the pads he suggested. Pelican turned out absolutely amazing! Her gelcoat was chalky before we started, but we could see our reflection when we were done! It took a lot of time, but it was well worth it.
 
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