Badly oxidized gel coat

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High Fin

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Joined
Jun 5, 2017
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Any suggestions on how to make an old boat that has been in the weather shine? The gel coat is oxidized and I am having a hard time figuring out what to use. The internet has a ton of products that all claim to do a great job.

Thanks!
Rhonda
 
If it's really bad use 3M super duty rubbing compound, and a 3M compounding pad, has to be done by machine. In my yards we used 3M products extensively and found this the best for heavy oxidized gel coat. You can follow up with a restorer/ wax after and then you'll be good for a few years, just by using restorer /wax on a annual basis.
 
If it's really bad use 3M super duty rubbing compound, and a 3M compounding pad, has to be done by machine. In my yards we used 3M products extensively and found this the best for heavy oxidized gel coat. You can follow up with a restorer/ wax after and then you'll be good for a few years, just by using restorer /wax on a annual basis.

This is what I would do. It is a lot of work but very rewarding.
I have bought several boats that were very badly oxidized. I would compounded and waxed them when I got them home. It usually took a couple of weekends but they looked great when I finished. I would then use them for the summer and sell at the end of the summer for several thousand more than I bought them for.
 
If really bad it saves time to start w wet & dry sand paper using a block. 1200 if bad followed by 1600 - 2000 grit. Or go to the diner to start if not too bad. Then compound then swirl remover in steps. It will take some experimenting to determine how aggressive you need. Gosl should be to start with least aggressive starting step that doesn't take an excessive time to get improvement. How manyk steps depends on where you start. Using proper pads for cutting is also key.
Lots of help info & videos online.
There is no miracle one step product if badly oxidized.... IMO
 
You will definitely want to use a buffer. 3M makes excellent products. Like Martin J says rubbing compound if it's really, really bad. Or if it's just bad then a compounding product will work. The difference is how much grit they have in them. This will be a three step process. Step two would be to apply a polish. This will restore the shine. Step three is to apply wax, which will protect the polish. Do some research on the type of pad to use on the buffer for different products. If you use foam pads they will actually provide a little cut too. Different colors have different uses.

If you use a regular buffer you need to be extra careful about getting the surface to hot and burning it or actually removing excessive gel coat, especially on edges and corners. I use a Porter Cable random orbital buffer. Much more user friendly for the DIY.
 
Another vote for a good buffer and 3M, my boat was in that condition when I bought it, never waxed or buffed. It took one heavy pass of 3M Heavy cutting compound to reach the shine, and then another of 3M Finessit to really bring back the original color and shine. I bought a Makita buffer, where you can lock the trigger and vary the speed with the knob on the grip.

I wind up Finessing every other year and applying a coat (or two) of wax to make it shine. Mostly the buffing removes tar and rub marks from the fenders and dock after the first buffing.

It's a whole lot easier to do when it's on the hard, and you can stand in the back of your truck and drive around the outside of the boat buffing :)
 
i would take a trip to Fishery Supplies and talk too the guys there.
They will not steer you wrong.
 
My regimen for oxidized fiberglass is to wet sand with dual-action polisher, polish with 3M Finesse-It, then wax and buff. I use a Harbor Freight 6" DA polisher ($60), and have a 5" hook and loop pad. Use 5" 400, 1000, and 2000 grit hook and loop discs. Use a spray bottle with water and a little Dawn to keep the area wet while sanding. I use the DA polisher 6" foam pad to apply the Finesse-It, then buff it off with microfiber towels. I finish up with Collinite wax applied and buffed out with microfiber towels by hand. I prefer to wax and buff by hand because it leaves more wax on the surface than would a power buffing polisher.
 
If an older boat and badly oxidized, you may be better off letting a pro do it..... Unless you are very experienced.


I have seen wayyyyy too many gel coats ruined by going too far and now you either refel or paint. I did a lot through the years and still went through the gel on really bad boats and even some not so bad boats but ones that had thin gel.


Better someone else doing it than you. .. it's a tossup for sure.
 
Do all you can to try and save your gelcoat before considering paint. Gelcoat is more durable than even the best paints.
 
Some good advice here so far.
Have done it all including wet sand rubbing compound etc.
If it’s too far gone, Poly Glow is an excellent alternative.
Works as advertised look it up on Google.
In my experience it will degrade and yellow some after a while, but the good news is it washes right off with their Poly Prep or industrial wax stripper, then just apply another coating.
 
I used 3M Imperial, which 3M says combines medium aggressive cutting with a polishing action....no swirls. It works! One step. Depends on just how bad the oxidation is on your boat, but I'd try a quart of Imperial before going to a heavy cutting compound and then having to do a second pass with something like Finesse it. I used the big, cheap variable speed polishers from Harbor Freight. Wore out the gears in one out about 3/4 through the job.. Still have the second one. But you need the variable speed feature. Think I used a white wool pad versus the yellow (whichever is the least aggressive of the two). There's a special tool to clean the dried compound out of the pad on occasion... a screw driver works, though. Hard on the arms and shoulders....
 
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"Gelcoat is more durable than even the best paints."

I am not so sure of that, many top yards seem to prefer paint on new GRP boats.

Marlow? Abeking & Rassmusen?
 
Peter: :thumb:

What’s the expected life span? How are repairs made, if needed?

Larry, the lifespan depends on location (sun exposure)- 3-5 years towards the tropics, and 8-10 years in northern climes like Seattle.

The film is a basecoat/clearcoat 3M product, so fade in minimal if at all. Simply cut out the damaged area, cut a new piece slightly larger than the cutout, clean the hull with alcohol, and apply the patch.
 
Visit this website. I use the Dual Action Pro-polisher and some "Buff Magic." Talk to the folks at Shurhold. They are very happy to help you. They also have instructional videos. I use this stuff and found it to be awesome! I have no interest in Shurhold other than their stuff works.

https://shurhold.com/collections/dual-action-polisher-pro
 
I've seen Peter's boat. The wrap looks terrific.
 
Larry, the lifespan depends on location (sun exposure)- 3-5 years towards the tropics, and 8-10 years in northern climes like Seattle.

The film is a basecoat/clearcoat 3M product, so fade in minimal if at all. Simply cut out the damaged area, cut a new piece slightly larger than the cutout, clean the hull with alcohol, and apply the patch.

Thanks Peter. I like the repair process.
 
High Fin,
Check out marinehowto.com. Rod Collins (owner of that site) really knows his stuff.
I have followed his advice (in this case for boat exterior maintenance) for years. I have even had people in boatyards stop and tell me how great my boat looks, even before I have started this year's treatment.
According to Rod, there is no shortcut, it is a lot of work. Presta Chroma makes some great products for cutting and then polishing. Yes they are separate processes. If you try to just cut then wax, your result will not last as long as if you take the time to polish out the micro ridges that cutting puts into your gelcoat. I use a Makita polisher with the right pads for cutting and polishing.
Like another poster stated, I too use Collinite Fleetwax paste wax hand applied and taken off by hand with a microfiber cloth. If you use 2 coats, the wax will bead up for over a year. The secret to the wax application and removal is to do small sections at a time and use a water bottle to mist the surface just prior to applying the wax. Remove when the surface is about 70% dry. Do not let it totally dry or removal will be hard work!!:)
Rod's article on this subject goes into great depth on this subject.
Good luck,
Tom
 
I second Tom's recommendation to check out Rod's (CMS, Mainesail) website. He has a great write-up on how to do it. I read it carefully, educated myself, planned out the project... then paid a professional to do it for me. If I was retired, then I would consider it, but hard work gets harder the older I get and I have too little time to enjoy the boat as it is.
 
First, make sure you're looking at oxidized gelcoat and not a previously painted finish. I tried buffing my 'gelcoat' unsuccessfully, then I realized it had been painted. In which case, the only solution is to sand and repaint.
 
Waxing vs Poli-Glo

I've compounded 2 sailboats and painted 3. Now I own a Nordic Tug 32.
I recently used Poli-Glo on the green hulled tug. It looks fantastic and didn't kill my shoulders. Compounding and wax are an incredible amount of work to get the right look. Compounding removes gelcoat. Sooner or later you don't have any gel coat left. I put 5 coats of Poli-Glo on in one day and Bruno looks great. In my Northern Michigan climate I'll do one coat a year. Just one guy's opinion who has boated his whole life.
 
I have restored many gelcoat boats in my time. I have been in the auto reconditioning business since 1975. as a part of my business boats, rv's etc were routine customers.
in 2011 I became part of the marketing and sales department of the buffpro polisher. see buffpro.com for videos of this polisher in action. it will not burn gelcoats or paint, it will not leave swirl marks and is so easy to use I can train someone to use it in five minutes.
it will accommodate heavy cut wool pads , medium cut foam and polishing pads. it is far less expensive to detail your own boat than to hire detailers or to wrap the boat. take a look at their website. there are also videos on youtube.com I believe.
 
Heres the easy way out--I did it with my Dyer sailing dinghy and it had a mirror like reflection. Lasted about 6 months. Power wash or otherwise clean it completely. Apply 3 coats of Zeb floor polish from the depot. Just wipe it on with a soft cloth. No work, no buffing etc. No expensive marine products. Works on any size boat I suppose. JP
 
Some will say I am crazy but this works, we have had 2 Red oxydized hulls on Sailboats my sweet wife using her logical brain correctly deduced the hulls needed moisture she would Use Vaseline on the hulls, it worked like a charm, but did cause concern once with a surveyor that detected a petroleum based product on the hull, we had no money and it sure made the boats look ,like new.
 

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How we polished our boat

The bottom of our boat has never been painted. We used an orbital polisher with buffing compound. Then polished it. If there is still oxidization go over it with 1000, then 2000 grit sand paper and repeat the polishing. IF its really bad you may have to pay. We are on a shoe string budget, so we try and do things ourselves. Each time we take it out of the water, we clean it really well so the are no water stains from the murky lake water.
 

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