Boat detailing - how to tell gel coat failure/burn through, or just oxidation that needs correction?

[jmorlan]

I have a centurion that looks to be oxidized, but the gel coat may be failing, I am not sure.

What products/pad combo would be best to give it a shot at life again? How do I tell if I'm over doing it and killing the gel coat?

I've never polished a boat before and I fear the gel coat may be a lost cause. I also do not want to be over zealous, and ruin it lol.

Any help would be greatly appreciated guys.

I'm getting my boat in shape in preparation for starting on my folks' boat, which is much larger, and much more expensive if I screw up.


The oxidation, or failure is not on the bottom hull itself, but up above on the upper area of the boat, the area where if you lean your arm over, it would touch the boat, if that makes sense.

I will try to throw up some pictures tomorrow to show the condition

Ill be using a PC7424

[SuperiorAutoLLC]

I have a centurion that looks to be oxidized, but the gel coat may be failing, I am not sure.

What products/pad combo would be best to give it a shot at life again? How do I tell if I'm over doing it and killing the gel coat?

I've never polished a boat before and I fear the gel coat may be a lost cause. I also do not want to be over zealous, and ruin it lol.

Any help would be greatly appreciated guys.

I'm getting my boat in shape in preparation for starting on my folks' boat, which is much larger, and much more expensive if I screw up.


The oxidation, or failure is not on the bottom hull itself, but up above on the upper area of the boat, the area where if you lean your arm over, it would touch the boat, if that makes sense.

I will try to throw up some pictures tomorrow to show the condition

Ill be using a PC7424

Hello!

First of all, I think you will find that oxidation removal on a boat is a really fun thing to do; I really love seeing a boat come back to life.

Start with a regular wash using a product that's safe for gel coat. I highly recommend checking out some of AutoGeek's new line, Marine 31. I have tested some products in that line and so far I have been thoroughly impressed and I think you will be too. Use a good APC (all purpose cleaner) and a soft brush to remove any mold or mildew from the side of the boat.

You won't have to worry so much about inflicting any damage to the gel coat using a PC 7424; remember, gel coat is harder and more forgiving than clear coat.

Check out my thread on oxidation removal here: 21' "Calusa" Boat Oxidation Removal - Complete Makeover!! LOTS OF PICS!!

Start with this: Marine 31 Gel Coat Heavy-Cut Oxidation Cleaner, fiberglass compound, gel coat compound, marine oxidation remover using an aggressive foam pad on Speed 6. You really should be using a rotary buffer for the compounding step, but your PC may work if the oxidation is not too severe. Follow up using a less aggressive pad in conjunction with this: Marine 31 Gel Coat Final Step Polish, boat polish, gel coat polish, fiberglass boat polish. Keep your speed between 4000 and 5000 RPM, making overlapping motions and gradually reducing your pressure until you see that mirror-like finish once again.

That should get you off to a good start. Remember to work in a small section at a time (2' x 2') and take your time. This is not a quick and easy process and may take you a couple of days to get the finish you want.

You are more than welcome to PM me with any questions you have along the way, and I am more than happy to help.

Good luck and post pics!

[jmorlan]

How do I know if the gel coat is toast or just oxidized?

I know I shouldn't say, but I have Adams polishes, will that do the job, or do I need a more aggressive polish?

Ill be sealing it and coating with collinite fleet wax.

[jmorlan]

Also, the oxidation is above the rub rails only, the hull itself is in great shape. Should I be waxing the hull as well? my guess would be yes.

Im not afraid of killing the gel coat with my PC, I am afraid it is dead already.

[SuperiorAutoLLC]

Im not afraid of killing the gel coat with my PC, I am afraid it is dead already.

You will need to snap a few photos for us to see.

[Mike Phillips]

How do I know if the gel coat is toast or just oxidized?

I know I shouldn't say, but I have Adams polishes, will that do the job, or do I need a more aggressive polish?

Ill be sealing it and coating with collinite fleet wax.

Gel-coat tends to be very thick as compared to the clear layer of a clearcoat paint job. This means you have more material to work with and in most cases you can easily restore the shine simply by compound off the dead, oxidized gel-coat.

You are going to want a rotary buffer, wool pad and aggressive compound to get started. Too thin of a gel-coat finish would be the least of my worries.

Do you have a rotary buffer?

[Mike Phillips]

Ill be using a PC7424

You can do it with a PC but if the oxidation is heavy then it's going to take a long time and you're only going to be able to work small sections at a time. You really need a rotary buffer with a wool cutting pad and an aggressive compound to cut off the dead gel-coat and get down to a fresh base.

[Mike Phillips]

This is an all original 1967 Starline Deville I shipped out here from California when I moved here. The hull was EXTREMELY oxidized to the point much of the gel-coat had turned chalky white.




Severe oxidation




Here's what I was able to do with a rotary buffer, wool pad and compound...










Marine 31 has an aggressive compound that with a rotary buffer will cut right through the oxidation and get you down to a fresh base of gel-coat to then polish to a high gloss.

I have an upcoming boat detail that I'll show step-by-step how to use the Marine 31 system.

Marine 31 Gel Coat Heavy-Cut Oxidation Cleaner

[allenk4]

Look at the inside of the hull....the backside of the piece you are going to correct. This should tell you what is underneath the gel coat.

In my Baja the fiberglass layer under the gel coat was black.

If you start to see the color change while correcting, you are getting close.

That being said; Mike is correct that the gel coat is very thick. I wet sanded 1st and finished with 7424 and 3M Marine compound (can't remember which one).

The good news is that even if you blow thru the gel coat, it can be spot repaired. A good shop can even color-match the "off-white" that poorly maintained gel coat can become. In Austin, you would be looking at $200-300 for a spot repair.

[jmorlan]

Thanks guys, I do have a rotary but I'm terrified to use it. I went around with it for a bit one day last year with the rotary and some mothers polish.
It just had a terry bonnet on, but now that I think, I question one of two things -
1. I made it worse and killed the gel coat?
2. I did nothing and only masked the oxidation until it dried out again and showed through?

I'm on my way in to work so ill make sure to snap some pictures of what I'm talking about when I get there.