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View Full Version : Gelcoat restoration experiment. Results not so good


Jeff d
06-17-2010, 01:16 PM
Well. I read up on here a lot about different people's techniques for shining up old gelcoat over the course of the last week.

My gelcoat isn't very oxidized but there are quite a few scratches. It's a 10 year old boat but I'd say the gelcoat looks more like a 5 year old boat. I've seen threads here where boats that looked 100x worse that mine actually turned out looking better than mine does at the moment. I reached the conclusion that I would compound and polish the whole hull and only wet sand the scratches.

My goals are to eliminate the small scratches, minimize the larger scratches, polish off the minor oxidation and, if possible make the area where the MariStar decals used to be blend with the rest of the boat. The lower portion of the hull is an off white/light tan and the upper is black with a 1" wide tan stripe below it.

I got this buffer from Harbor Freight for $27:
http://www.harborfreight.com/7-inch-variable-speed-polisher-sander-92623.html

I got this pad for the compounding:
http://www.harborfreight.com/9-inch-foam-buffing-pad-91235.html

And this one for polishing:
http://www.harborfreight.com/9-inch-black-foam-polishing-pad-91236.html

I already had some 3M Marine Rubbing Compound like this:
http://www.jamestowndistributors.com/userportal/show_product.do?pid=8563&googleaffiliate=

And this 3M "Restorer/Wax":
http://www.jamestowndistributors.com/userportal/show_product.do?pid=3888&familyName=3M+Marine+Fiberglass+Restorer+and+Wax

I also got some 600 and 1000 grit wet or dry sandpaper.

So, last night I decided to experiment to see if the compound and restorer/wax that I already had were sufficient. I started with the buffer on about 2,500 RPM and the Restorer/Wax. This improved the gloss and smoothness a lot but didn't touch the scratches or the color difference between the exposed gelcoat and the gelcoat that was behind the decals.

Next step was to try the compound, followed by restorer/wax. This actually turned out worse than just the restorer/wax. I ended up with a lot of swirly scratch induced haze that didn't buff out.

Next step I tried a small area where there were scratches with the 1,000 grit. With wet sanding it took the minor scratches completely off but when I followed up with the compound it couldn't take out the 1,000 grit scratches.

So, what do I need to fill in the gaps between the 1,000 grit, 3M Rubbing Compound, and the 3M Restorer Wax? Should I be using different pads on the buffer?

Thanks,
Jeff

oxberger
06-17-2010, 02:27 PM
Jeff, I haven't started my gelcoat resto yet, but have gotten a lot of good info on here about it. What you may need to do is move to a 1500 grit wet sand then 2000 grit wet sand, then use the compound, then the restorer, then wax. From what I gather its quite a time consuming process taking care of scratches on the gel coat, but well worth the time and effort when completed. It sounds like you're right on track with the 3M stuff. Good luck. Where in the Southeast are you maybe I could help? I'm not a professional but might be able to lend a hand.

Jeff d
06-17-2010, 02:31 PM
Where in the Southeast are you maybe I could help?

Thanks. Baton Rouge, LA

What you may need to do is move to a 1500 grit wet sand then 2000 grit wet sand, then use the compound...

Some other threads were saying that it was easier to use a more aggressive compound that it was to wet sand with 1,000+. Supposedly there are compounds that will remove 1,000 grit scratches, I'm just not sure what that would be.

oxberger
06-17-2010, 02:45 PM
Wish you you were closer, I'd help. I'm in Murfreesboro TN. I've heard some guys mention the the heavy cut compounds, but the guys that seem to have had the best results were the ones who went with the extra labor of doing finer grit passes before the 3M compound. If I remember right, one of the resto threads for the gel coat mentioned having put in 80-90 hours to bring it back to showroom. I believe they started with 600, then went 800, 1000, 1200, 1500, then 2000, then heavy cut compound, then a regular compound, then 2 coats of really good wax. I'm probably going to have to do that with mine since it's so bad, but I bet yours could be corrected with 1500, 2000, then the 3M stuff you have. Where are the guys that have done this already when you need them?

Napagary
06-17-2010, 02:52 PM
Jeff
Believe you're on the right track. I run my buffer at 900- 1000RPM, keep it moving over the surface with a light pressure. Keep the pad flat as possible, don't tilt it or try to put pressure on a trouble spot(ie compound build-up). You will have these trouble spots tho- move away from them and come back in 30-40 seconds. Do about a 2' square section at a time, apply the compound to the foam sparingly
I use 3M Perfect II Foam polishing Glaze, also the experts say the waffle style foam pad runs cooler than the straight foam. Idea is to keep the pad and compound as cool as possible.
Don't know how to guide you on the sandpaper grit. I have used 1500 & 2000 grit on a car I painted w/ clear coat but ultimately finished it with the 3M Glaze.
Wash out the pad w/ hot soapy water each eve, etc

Jeff d
06-17-2010, 02:54 PM
Found these videos:
http://www.youtube.com/watch?v=ke5kfYz9Ybw
http://www.youtube.com/watch?v=t0whDXwxYqk&feature=related

That 3M Imperial Compound & Finishing Material is crazy expensive though. $49 per quart at West Marine! The Finesse It isn't cheap either.

FrankSchwab
06-17-2010, 02:54 PM
I used Meguiars #49 (http://marinerv.meguiars.com/product/Gel-Coat-Clean) heavy oxidation remover on mine, and it cleaned up the surface remarkably well without a wet-sand. Your 3M compound looks to be similar.

Followed up with the Meguiar's #45 polish (http://marinerv.meguiars.com/product/Gel-Coat-Polish), and a good gelcoat wax, and it looked great (except where I buffed over the decals, and removed various colors and detail that shouldn't have been removed).

I bought the same polisher as you, except I used a heavy wool pad with the oxidation remover; something like what's described here (http://properboatcare.com/gelcocopa.html)

/frank

psychobilly
06-17-2010, 04:39 PM
IMO from what I've been told by guys who have done this procedure is NOT to wet sand. Wet sand as last resort. Use only the 3M compound and make sure to keep it damp...

Luv2Ski
06-17-2010, 05:03 PM
I second with the Meguirs marine products. I had really good luck with them, better than 3m though which left a lot of swirling. I used this kit (http://marinerv.meguiars.com/product/Specialty-Kits/Fiberglass-Restoration-System). In particular, the number 49 really breaks down well and it is surprising how good the shine it leaves is given the level of cutting it is initially doing. Even pressure and good speed selection is key.

One thing I will suggest is not being too afraid to go to a courser grit to get the raised letters off. My 88 had a very high raised area where the lettering was applied and I went all the way down to 400 in those areas. As new as your boat is, I doubt you will need to go to 400; however, if you are afraid to go under 1,000 you will be there all day taking out those raised spots. Also, use a pretty stiff sanding pad so that you don't follow the raised contours. I followed up with 600 then 800 (a few locations to 1,000).

<edit> For the most part I did not do any sandying, only in areas that were under graphics or needed gelcoat fixes </edit>

Then the number no 49 to no 45 and finally wax. Very happy with the results, maybe because it was horrible when I started (never buffed/waxed since 1988).

The color of the gelcoat makes a big difference. I had to work on the black a lot longer than I did the gray. While sanding use a squeegee to wipe off the water, that helps you see when you have sanded enough and can move to buffing.

Good luck!

sand2snow22
06-17-2010, 05:04 PM
I was told by the gelcoat guy at my dealer, all scratches have to be wet sanded. Are you talking scratches or swirl marks? Rubbing compound can bring the color back, but the scratches usually remain. I had him do a nasty scratch on my boat. He started with 400, then moved to 600 and finished with 2500, before applying a Meguiers automotive compound that made it look brand new. He hit some of the smaller scratches with 2500 wet sand, finished with compound. Slower speeds for compound.

BrianM
06-18-2010, 09:06 AM
Jeff this is what you need to do. If you are compounding you need to use three steps. If you have some deeper scratches you need to get those out first by wet sanding. Usually 1000 grit will do it but at most 600 followed up by 1000. I have had great luck with the following process for restoring gel. Sounds like yours is just in need of a polish and not a compound. In that case no need to compound the whole boat. Just use the compound over the areas that you had to sand out scratches.

3M heavy Duty Rubbing Compound with a Wool pad

3M Finesse It II with an Orange foam Pad.

Your favorite Carnuba Wax with a Red Pad.

My guess is you are on the right track but I bet those Harbor Freight pads are part of your problem. You need high quality pads. These pads are top quality http://www.properautocare.com/4inspotreppa.html

I'm in Mandeville if you want some helps hoot me a PM.

Jeff d
06-18-2010, 09:31 AM
Polishing doesn't seem to have any affect on the color difference under the MariStar decal. Should I just buy new MariStar decals or is there much hope of reducing that? My female cousin thought it said ManStar because of the font and the "r" being right by the "i". I don't want to be a ManStar!

Luv2Ski
06-18-2010, 09:47 AM
I would be surprised if you can't even out the color on a white gel coat like that. Sand flat, cut, polish - lots of good advice on this threat - just keep trying different methods till you find what works.

I second the pad being part of your problem. Use a good 3M or Meguiars pad (I have had good luck with the Meguiars foam pads - they make one for each type of compound). The backing plate is important as well, the ones that come with inexpensive buffers are really stiff and make it hard to apply even pressure.

BrianM
06-18-2010, 09:51 AM
The color will even out if you use the 3M Heavy Duty Compound on a wool pad. The compound starts out pretty abrasive but breaks down and reduces the amount of light compound scratches. I was easily able to bring back all of the shine with the Finesse It II. Look at the results I got here http://www.mastercraft.com/teamtalk/showthread.php?t=19557&highlight=restoration

Jeff d
06-18-2010, 10:00 AM
Look at the results I got here http://www.mastercraft.com/teamtalk/showthread.php?t=19557&highlight=restoration

Oh, that was one of the threads that inspired me.

BrianM
06-18-2010, 10:03 AM
Pads I think are your issue. I bet the pad you are using with the compound just isn't 'cutting' it. Too soft a pad isn't going to get it done.

atlfootr
06-18-2010, 10:38 AM
BrianM's right on track .. these pad's he's recommended are the ones to use.
http://ep.yimg.com/ca/I/classic-motoring_2108_3497670

atlfootr
06-18-2010, 10:40 AM
And remember Jeffd, some of us want to see your hard work ... don't forget

americanskierJim
06-18-2010, 11:49 AM
Get a better wool pad from you local automotive paint store and a diffrent finial pad it would help you out alot. I am a body shop owner and I am just saying the pads you have I wouldnt use. As everyone is saying get some 3M compound and go nice and slow but do it in the shade not in the sun. Keep up the hard work it will pay off.

Jeff d
06-22-2010, 07:12 PM
I did some more experimenting and those who cited the cheap foam pads and the stiff backing plate as the problem were right.

I used the Harbor Freight "wool" pad with about a 1.5" soft foam backing that was included with the buffer and it was so much easier to manage than the foam pads. The foam pads would grip the hull, create a lot of friction, jerking me around and drying out the compound pretty quickly.

The "wool" pad was much smoother, conformed to the surface and kept the compound liquid longer. It allowed the compound to cut better and the end result had fewer swirl marks.

This is still a low quality pad but I can now see how much difference the pad can make.

New pads and more compound aren't in the budget right now with all of the other needed fixes so I'm just going to put a good coat of cleaner/wax on there and defer the complete restore until next season.

oxberger
06-23-2010, 09:19 AM
Jeff, glad you were able to figure out what works for you. Can't wait to see the pics when you decide to do it completely. So what's the next thing you'll be working on?

Luv2Ski
06-23-2010, 09:40 AM
Just FYI, nothing wrong with a good quality foam pad, the new generation foam actually leave fewer buffing scratches than the wool ones. A good wool or foam pad will only run you about $10, you will want one for each type of compound you put on.

It is tough to work on the boat when the sun is scorching... better to be out there on the water! Good luck with your other projects!

Jeff d
06-24-2010, 11:08 AM
So what's the next thing you'll be working on?
You can check out my other thread here:
http://www.mastercraft.com/teamtalk/showthread.php?t=36048

slickwater1
06-26-2010, 10:12 AM
wet sand it. period, start out with the lower grits and continue to get fine. It will scare you at first because it will look like you are taking way more off than you really are. After wet sanding use your cutting compound and then a high quality buffing compound and then wax. It takes time and sweat but it will make your boat look like a brand new one.

Campbell
07-05-2010, 09:08 AM
If all else fails......"3m superduty" compund ,, by hand will work and not make the mess your buffer will. " 3m Perfect It " with buffer to finish off.

Jeff d
07-24-2010, 07:32 PM
There was an area on the port bow where there were significant scratches about 5 feet long. It looked like they rubbed against some protrusion on a dock. I've been working a couple of nights a week over the course of the last few weeks to sand those out and finally got it to the point where I'm satisfied.

These scratches looked like they were through the gelcoat but I experimented and found out that they weren't. The final process that I ended up using was wet sanding with 400 grit (Folded in 1/4s to target the scratches) until the deep scratches were nearly gone and then followed up with 800 until they were completely gone. Then I wet sanded with 1,000 on a sanding block and finally 1,500 grit. Then I hit it with the 3M rubbing compound and the buffer until there were no more sanding marks. Then I used the 3M restorer wax.

I expected it to take a while but it exceeded my expectations. I'd guess that I spent probably 8-10 hours just working that small section of the hull.

This was the biggest eyesore on the boat and it's gone now. If you look really closely you can see the occasional portion of the scratch remaining at areas where I was scared to go deeper. There's a couple of places where it was definitely through the gelcoat but it's immediately under the rubrail. From 5' it looks pretty much perfect.

I'm not going to do a complete restore for now. I'll probably consider doing it in the winter because I'm killing myself doing this in Southern Louisiana during the summer even if I wait until after dark. For now the boat looks 80% better and I'm pretty happy with that for the remainder of the season.

ramzak
07-28-2010, 02:55 AM
I just restored my hull.

The over the counter crap you buy at West Marine, Auto Parts Stores, Academy, etc... Is not enough. These products are meant for the everyday idiots so they cant mess anything up.

What I did and what you need to do is...

Find the worst part of your hull.

Do a small area first to determine your depth of damage/scratches.

All WET!!! All with a hard foam block, no fingers!!
Start with 1200.
If that does not work, move to 1000 grit.
If that does not work, move to 800 grit.
then 600, then 400, then... Untill you find the grit that matches the degredation of your hull.

Once you do that...
move up in grit and redo the hull.
For example if 600 gets you where you want, then do it again with 800, then do it again with 1000, then do it again with 1200, then 1500, Maybe even 2000.

Finally go to a Auto Paint and Body supplier like TASCO and get the Black cap 3M Rubbing Compound. It says it is equivelent to 1200 grit. I know you already did 1500 or 2000 wet sand but that doesnt matter. Go over it again. Then go over it with a glaze and finaly some wax a couple of times.

Should look better than new!

hosofpayne
07-28-2010, 06:25 AM
What did you use for glaze and how much 3m to do whole boat? thanks THIS SITE RULES thanks to everyone ......info is invaluable

wtrskr
07-28-2010, 10:53 AM
I'm getting ready to do my '94 prostar 190. It is pretty heavily oxidized. My plan:

1. Wetsand
-Planning on starting with 600 or 800 then do 1000

2. Compounding:
-Harbor Freight Wool Pad (not the nylon polish pad that came with the Harbor Freight polisher)
-3m Rubbing Compound

3. Polish:
-3M foam Pads
-Finesse It II

4. Swirl remover (not sure if I'll do this step)
-Same 3M foam Pad
-Meguires #9 swirl remover

Any feedback on my thought process? I haven't started the project yet so I can use other products. I assume that the Marine specific 3M products are better for boats but I've also heard you can use the car compounds too. Which is better?How much sandpaper should I expect to need?

Jeff d
07-28-2010, 10:57 AM
On the 3M demo video they used a pneumatic sander and fine grit papers first. They did this dry. Seems like it would save a lot of elbow grease. Any reason not to go that route if you needed to start with a lot of sanding?
http://www.youtube.com/watch?v=ke5kfYz9Ybw

wtrskr
07-28-2010, 11:28 AM
I'd be curious to hear opinions on the pneumatic sander too because it sounds like it could save a lot of time.

Sodar
07-28-2010, 12:22 PM
I have seen the local gel place use the pneumatic sander and it does look very easy in flat spots without any contours. I have never seen the type of backing pad they use in the video. It looks thick enough to be able to assist with contours and hull lines. Cool stuff.

Laurel_Lake_Skier
07-29-2010, 10:34 PM
I'd be curious to hear opinions on the pneumatic sander too because it sounds like it could save a lot of time.
They use a lot of air so a big air compressor is needed to keep them running. The advantage over an electric model is lighter weight of the air powered units. But unless you already have an 8-10 hp compressor, the cost of the compressor along with the pneumatic sander will be pretty steep.

wtrskr
07-29-2010, 10:44 PM
That answers that. I'll be sanding by hand. Thanks.

Luv2Ski
07-30-2010, 10:07 AM
You can use an electric random orbital as well; works about the same as the pneumatic but weights a bit more as mentioned above. Just be sure you get good DA sand paper (like 3m) and be sure you have a flat pad on your sander as it does remove material pretty fast. I used an electric on several spots when I did mine.

1985 Skiier
08-05-2010, 01:07 AM
Thanks for all the info, I am working on the bottom of my boat where it rides up on the carpet and causes small scratches. I have been working with a 3m scratch remover compound and it is getting better, but taking forever. I think the old Mouse sander and a 1000 grit may do the job. I just bought an 85 garage queen and the owner was quick to point out the two 1/4 inch chips near the bow eye and one small scratch on the A decal passanger side. I am feeling pretty lucky. He did not realize what he had. I will post pics soon. Speaking of small chips any one have any suggestions on matching gel coat/ filling small chips? 1985 bage

Luv2Ski
08-05-2010, 11:50 AM
Speaking of small chips any one have any suggestions on matching gel coat/ filling small chips? 1985 bage

I went ahead and purchased a container of gelcoat paste (http://www.discountmarinesupplies.com/product.cgi?group=71337&product=83563) and a full set of tinting agents (http://www.discountmarinesupplies.com/product.cgi?group=71336&product=104621). You could also go for the kit (http://www.discountmarinesupplies.com/product.cgi?group=71337&product=83566), but you get WAY more product for just a few more $$$. The tinting agents can be used for all sorts of future projects as well.

In terms of the process, here are a few tips:

Completely buff a nearby area so you know exactly what you are trying to match.
Mix your coloring agents on a white mixing board, a little bit goes a long way
As you mix, put some right on the existing gelcoat surface you are matching and compare, wipe off immediately
Mix a large enough batch to be sure you don't run out mid job
Once you are happy with the color, separate the amount you are going to use on the first repair, then add the hardener just to that amount. That way all of your repairs will have exactly the same color.


You might also check out these guys (http://www.google.com/url?sa=t&source=web&cd=2&ved=0CB0QFjAB&url=http%3A%2F%2Fwww.spectrumcolor.com%2F&ei=1dxaTL2iIYL58AaS1c2MAw&usg=AFQjCNHrrVy6iMzjbmdtPZm9rdF1juy2HQ). They have premixed gelcoat by boat. On older gelcoat you are probably safer mixing your own.

<edit> I noticed the gelcoat paste was link was pointing to a non-paste product, link has been updated, hopefully that did not lead to anybody purchasing the wrong product - sorry </edit>

psychobilly
08-27-2010, 02:40 PM
Jeff this is what you need to do. If you are compounding you need to use three steps. If you have some deeper scratches you need to get those out first by wet sanding. Usually 1000 grit will do it but at most 600 followed up by 1000. I have had great luck with the following process for restoring gel. Sounds like yours is just in need of a polish and not a compound. In that case no need to compound the whole boat. Just use the compound over the areas that you had to sand out scratches.

3M heavy Duty Rubbing Compound with a Wool pad

3M Finesse It II with an Orange foam Pad.

Your favorite Carnuba Wax with a Red Pad.

My guess is you are on the right track but I bet those Harbor Freight pads are part of your problem. You need high quality pads. These pads are top quality http://www.properautocare.com/4inspotreppa.html

I'm in Mandeville if you want some helps hoot me a PM.


BrianM,

I followed your advise and MAN, WOW!!!! LOOKS LIKE A BRAND NEWWY!!!!!

I don't know WHY anyone would waste their time "wet sanding"!!! My 240SC had that ole chalky crap all over it and the green looked aqua. After following your advise it now looks green and the red is red instead of pink.

That DeWalt variable speed grinder and compound pads deal off ebay was 250 bux well spent. I will say it took me about 5 1/2 hours to do three different compounds on the ole 24 footer.... I still need to get some of the plain ole wax and go over it again, but man thanks a million!!!!! I'll take some shots of it tomorrow and post. ***Where's those guys holding that sign when you need it*** ***thinks to self, it's just a matter of time and someone will prolly post it... lol***

Thanks again Brian!!!

BrianM
08-28-2010, 10:40 AM
Glad it worked for you.

psychobilly
09-22-2010, 04:20 PM
Here's some of my results as promised. Now before everyone gives me grief about it being on the boat lift, that's the only way I could get the bottom done. I had the "Boat Guys" do it fer 100 bux. I did all of the rest of the boat. It took me 6 hours to do it and I still have to go over it again.

61893

61894

jvbaca
09-23-2010, 09:05 AM
Looks great, good job!

Jeff d
03-14-2011, 12:48 PM
I got some 3M "Imperial Compound and Finishing Material", some "Perfect-It Machine Polish" and a superbuff 5703 pad on Friday. Worked the boat some over the weekend and I'm getting outstanding results compared to the "over the counter" 3M stuff I was using before.

I had to sand the unfaded decal spots with 600 through 1000 grits to get rid of those. The compound alone wasn't enough for those spots but I didn't have to sand anything else.

I'm only about 1/3 done and it's a whole lot of work. I'll post pictures when I'm done.

kskonn
03-24-2011, 01:51 PM
for what it is worth in the future, the company I am sales rep for is one of the largest 3M distributors in the country. I sell a lot of the mentioned products in this thread to a number of boat manufacturers and service shops. If you ever need anything let me know, I can probably order up a sample or at worst get you some stuff at a largely reduced price.

I did my boat a few weeks back, I have owned it for a year and it was completely flat with no shine, I removed the decals and compounded it and waxed it with 3M show glaze, here is a pic of the finished look, I will put a pic up later with the new decals.

psychobilly
01-18-2012, 05:20 AM
for what it is worth in the future, the company I am sales rep for is one of the largest 3M distributors in the country. I sell a lot of the mentioned products in this thread to a number of boat manufacturers and service shops. If you ever need anything let me know, I can probably order up a sample or at worst get you some stuff at a largely reduced price.

I did my boat a few weeks back, I have owned it for a year and it was completely flat with no shine, I removed the decals and compounded it and waxed it with 3M show glaze, here is a pic of the finished look, I will put a pic up later with the new decals.

kskonn, I was reading through this ole thread and noticed you never posted up any pics of it with the decals back on her. How about some of that 3M show glaze??? I just over in houston, you have any samples???? :-)