Gel Coat Kits Good or Bad

Highlife

Seaman Apprentice
Joined
Jul 24, 2011
Messages
44
Has anyone ever used one of those Gel Coat Restoration kits like Vertglas or MS Gelcoat? I have a 1991 fiberglass boat that I would like to bring the shine back to. I don't want to wish I hadn't checked with you all before using something like this on my boat, if you know what I mean, it's better to get good advice from a forum than figure out how to fix what you just messed up. Any advice or thoughts are greatly appreciated. Thanks
 

Highlife

Seaman Apprentice
Joined
Jul 24, 2011
Messages
44
Just bring the shine/luster back to the oxidized boat, I have tried buffing with a 3M oxidizer remover cleaner and it helped, followed that up with a good waxing. That all helped but it doesn't seem to bring the luster back to the finish.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Just bring the shine/luster back to the oxidized boat, I have tried buffing with a 3M oxidizer remover cleaner and it helped, followed that up with a good waxing. That all helped but it doesn't seem to bring the luster back to the finish.

Okay, now you changed things a lot. IF you do decide to go with new gel coating to bring your hull back to life, you now have to contend with the "WAX" you applied to see if you could make it shine again. If you plan to regel coat your boat, you are going to have to completely remove all the wax and old gel coat that is chalking up. You have to get down to good gel coat or fiberglass for a solid clean trouble free base to work from. Others more familiar with gel coating will chime in here and explain the procedures better...
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
I've tried a lot of the one step compound, oxidation removers, polished.... Nothing works better at removing the oxidation and bringing back the shine than wet sanding then buffing out with a good quality compound, then polish, then wax. This is the work I did yesterday. This is a 19 year finish that I don't believe was ever taken care of very well. Lots of scratches and heavily oxidized. Hard to tell in the pic how well it came out but the finish after the sanding and compounding is pretty dam close to showroom I think.

 

Highlife

Seaman Apprentice
Joined
Jul 24, 2011
Messages
44
Further, I can't see the pic, would love to see how yours turned out. I guess, I'm a little nervous about sanding, don't know enough about FB and how hard I can sand. what types grits of paper to use. wet sand with 500 then 1000? Plus don't know if it makes it easier that the boat is white? what type of compound did you use? hand rubbing or buffing?
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
Not sure y u can't see the pics. Anyhow, the amount and aggressiveness of the sanding depends on what condition ur gelcoat is in. U should start with the least agressive and see if it gives you the results you want. I'm using 600 then 800 then 1000 then 1500, but not everywhere. I'm doing this where it's heavily oxidized and scratched up. Some areas I'll skip and go right to the 1000/1500. After the sanding wipe all surfaces down w acetone then I'm using 3m imperial compound and finishing on a wool pad on a buffer set at 1500 rpm, then 3m finesse it polish on a foam pad then paste wax by hand.
Here's what I'm starting with.


Finish comes out very nice with this process.
 

Highlife

Seaman Apprentice
Joined
Jul 24, 2011
Messages
44
Further, very nice, was able to see the pictures finally. Recently got a new computer and still trying to figure out Windows 8. would you recommend just sanding a small area, then compound, then wax and followed up with paste wax or could a guy do the whole side in stages like you did? or is just personal preference?
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
Best to work in small areas like a 2' x 2' or so when compounding. For the sanding i'm going through the entire boat with each grit and going heavier in areas where there are more scratches. Really depends on what you're starting out with as far as scratches and oxidation. Best to try the least aggressive and see if it does what you want. Start with the compound and if its not enough, move to 1500, then 1000, then 800 etc. etc. Once you figure out what you need to start with, go through the entire boat with that and progressively go up in grit until compound and polish. Then seal it up with a good wax.
 

Highlife

Seaman Apprentice
Joined
Jul 24, 2011
Messages
44
Ok, sounds good. Now here is another question.... When your sanding are you going back and forth or in a circular motion? Can you tell i'm nervous about sanding my boat... i know if i want the results you are getting i have to...i appreciate you help in this.
 

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
I'm sanding both back and forth and in circular. Doesn't really matter I think. Maybe someone on here had more insight on this but it didn't really matter on mine. The finer grit paper takes out the sanding marks from the coarser grit paper and then the compound does even more so. The compound is equivalent to like a 2500 or 3000 grit from what I've heard and does a nice job at taking out the rest of the marks.
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
I have seen some crazy threads on buffing out boats ( been apart of them too ;) )

I would try using a wool buff pad and some compound first. You really have to press hard though. Your actually heating/melting the surface. I mean..not like taking a torch to it or anything..but microscopically your Melting the plastic..and 'rubbing' it.

Most times I find that the faded out crappy look is actually hammered out Wax or some other goofy product. Think of it like your skin. Oh..you say its all dried out and icky looking? Well just rub some moisturizer on it and your golden. Yea right. Sure it looks better..but didnt do anything for your skin. Just filled it up with oils and looking all GQ now. What you need to do ( same with gel ) is get it back to its fresh shtuff. Now if a buffer with compound wont do it..yea wet sand ( or vac dry sand if you want ). Doesnt matter what direction you go with...but yes..you should be going in a circular motion. You can certainly buff out 600 grit scratches..but aye..800 or 1000 doesnt take as much elbow grease on ye ol' bod. When I was younger I would rub out 600. Now Im smarter and do a quick cruise over with 1000 after my 600.

Oh..and not to start an argument, but put a good 'sealer' on it if Anything. Not wax. Wax is bad mojo for gelcoat. Not fine enough to work into the pores. ( again with the skin analogy..cool fresh clean skin? Great..put some moisturizer on it ! .. Mmm K )

Good luck and show us some selfies :)
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
I have seen some crazy threads on buffing out boats ( been apart of them too ;) )

I would try using a wool buff pad and some compound first. You really have to press hard though. Your actually heating/melting the surface. I mean..not like taking a torch to it or anything..but microscopically your Melting the plastic..and 'rubbing' it.
:)

This is not how you should buff gel coat, you do not want to push hard and generate heat, and the goal is not to "melt" the gel coat. Gel coat is not a thermo plastic that can be heated and reshaped without damage.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
When you "polish" anything, be it wood, metal or even gel coat, you are actually grinding off old surface material and getting down to a better material. If you have enough material to accomplish that without going through the material, you can make it shine again. However, if the material is defective too deep, there is nothing going to bring it back to a nice colorful shine again. So many try the polishing method and it looks fair for a month or two and then looks dull and faded again. And that is because the material is already destroyed and the effort only smoothed the surface for a little while. So if that is what you are doing and it doesn't last, your only option is to prep for a new finish... Unless you like the looks of bare fiberglass!
 

Yacht Dr.

Vice Admiral
Joined
Feb 26, 2005
Messages
5,581
Well Ondarvr..I dunno. I dont know exactly the melting point of cured gel is..but Im getting it pretty hot myself. Sure sure ive burned gel before. I mean..we do melt clear in topcoats to blend. I know its different stuff and all. In any case, I have a vimeo vid uploading of me doing some rubbing for you guys. PB kept wiggin out..and good lord I didnt think it was going to take an hour to upload. Will do post when its finished baking. ( Now if I can just figure out how to imbed the vid here )
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
As manufacturer of gel coat and resin, plus doing tech service for the products, along with doing instructional classes with 3M, Farecla and other buffing compound and wax suppliers, I can assure you that melting the gel coat is not part of getting a good shine. Heat is the enemy of gel coat, it can do all kinds of strange things, we even demonstrate it easily in a classroom training session. One of the demonstrations we do is to use an IR temperature gun to show how rapidly a buffer can over heat the surface.


PS. There is no "melting point" for gel coat, again, it's not a thermo plastic. You can slightly soften gel coat with heat, but there is a fine line between making it softer (not melting) and weakening the molecular structure so much that it's permanently degraded. .

The over heating can cause shrinkage of the gel coat and resin in the laminate which creates surface distortion and/or discoloration.
 
Last edited:

further

Lieutenant Junior Grade
Joined
Jun 18, 2009
Messages
1,031
Isn't that why everything I've read about using buffers says to use them on slow settings with compound so as to not get it too hot?
 
Top