Wet Sanding - effects on Fiberglass and a few test photos

[jmunro123]

My take.
Compound first-If not happy try the highest grit sandpaper-1000-1500 then compound again.
I've actually compounded out 400 grit scratches with a rotary buffer and my regular compound. I wouldn't do that on a flat surface though. This was small repair areas.
We have some areas that had heavy oxidation that actually gave the gelcoat a pitted appearance-base of the side windows. The first couple of years I basically shined up the pitted area but the texture remained. This area seemed to fade faster then the unharmed areas. Over the years and more compounding has eventually smoothed out the damaged ares and they hold up much better now. I do think severely chalked gelcoat will fade quicker UNLESS it is wet sanded or compounded out. Then it should revert back to normal durability if maintained. My thinking is to stay ahead of any chalking because once it starts it seems to snowball.

Carver: Your boat looks great! I give ya bridge guys credit as thats ALOT of gelcoat to take care of!

The pitting is actually what I think has happened to areas of my boat. Its only on the curved part of the cabin top and really only noticable on the radius. I have tried compound and it will shine after doing that but the small (and I do mean small ) pitting remains. I think I will step back to 1500 and just do the radius then Meguiar Oxidation remover then Buff Magic then polish and wax - but even then its 4 times over the surface + washing. Its a ton of work but the results will be worth it. After this mess I will be fine from here on in. Its just frusrating right now.

I can't wait to do the hull - that wil be simple Buff Magic and Polish maybe wax.

 

[Skuza]

The "pitting" I refer to almost looks like a non skid texture. Of course not with that amount of depth to the texture.
Yes the amount of work to get it back is daunting but after that normal upkeep should keep it looking good for years.

 

[dpmulvey]

I bought an old Glastron that sat out for years and had severe oxidation. I decided to ditch because it had the metallic gelcoat and above the rub rail couldn't be salvaged. However, I practiced wet sanding with those exact grits and here's a few pics of the results. Same process stepping up to finer grits. I used Meguiars Ultimate Compound/Rotary. Finished off with Ibiz marine wax (family friend developed this stuff out of Pompano Beach FL...good stuff). Check out the shine under the rub rail.

This was great practice and glad figured I'd try the process out on a junker first. I was pleased. I would say it's not necessary to start at 800 grit on most boats. Only in severe cases.

Before:

After:

Nice work.


Looks like a Glastron Scimitar.

 

[jmunro123]

The "pitting" I refer to almost looks like a non skid texture. Of course not with that amount of depth to the texture.
Yes the amount of work to get it back is daunting but after that normal upkeep should keep it looking good for years.

Mine is not that bad - ours just looks like little scratches in the get. I am going to order a Rotory today.

 

[Skuza]

Make sure you get a BUFFER and not a grinder. Max RPM's should be 3,000. An adjustable speed model is preferrable. My max RPM's are never over 2,000. And you have to be careful as you can burn edges. Don't let that scare you just don't ride edges of the gelcoat when compounding but if you have to ease the pressure and slow down the speed. Gelcoat is tougher to burn than paint on a car-FYI. Also these things like to grab cleats, antennas and fabric REALLY quick and by the time you realize it you're either bleeding or something is broken!
Good luck! You'll love the results!

 

[jmunro123]

Make sure you get a BUFFER and not a grinder. Max RPM's should be 3,000. An adjustable speed model is preferrable. My max RPM's are never over 2,000. And you have to be careful as you can burn edges. Don't let that scare you just don't ride edges of the gelcoat when compounding but if you have to ease the pressure and slow down the speed. Gelcoat is tougher to burn than paint on a car-FYI. Also these things like to grab cleats, antennas and fabric REALLY quick and by the time you realize it you're either bleeding or something is broken!
Good luck! You'll love the results!

Thanks for the advice. I have stayed away from a Rotary as I have heard horror stories about the damage they can create but in my case I just need something to speed up this job.

I think I will be doing the folliowing with a variable speed Rotary:
1. light wet sand really bad areas with 1500 grit
2. compounding top of deck with meguires Oxidation remover #49
3. Buff Magic the whole area
4. Polish
5. I really want to meguiar wax it also but not sure I will have time or interest.

 

[Carver370]

Thanks for the advice. I have stayed away from a Rotary as I have heard horror stories about the damage they can create but in my case I just need something to speed up this job.

I think I will be doing the folliowing with a variable speed Rotary:
1. light wet sand really bad areas with 1500 grit
2. compounding top of deck with meguires Oxidation remover #49
3. Buff Magic the whole area
4. Polish
5. I really want to meguiar wax it also but not sure I will have time or interest.

Depending on what you are calling polish you can skip 4 or 5.

 

[wvsundancer]

Just one quick question when I ws at the Cleveland boat show this year I was told that you should put Buff Majic on wet and take it off while it is still wet. In other words just put it on and start buffing. Is that correct ?

 

[Carver370]

Just one quick question when I ws at the Cleveland boat show this year I was told that you should put Buff Majic on wet and take it off while it is still wet. In other words just put it on and start buffing. Is that correct ?

Exactly, do not let it dry. Although it would take a long time to dry anyway.

 

[wvsundancer]

The guy told me o use a paint brush to put it on is that correct ???

 

[Nehalennia]

Skip the wet sand, get a buffer (I like the Makita) with a few wool pads(one for each different product). Try Meguiar's 49 first, then 67, then switch to the Porter Cable 7424 and a medium pad with Starbrite Polish with PTEF. Buff off with a microfiber towel.

 

[Carver370]

The guy told me o use a paint brush to put it on is that correct ???

I use a short bristle paint brust to apply it. Make sure you do not use too much.

 

[Gunn]

The guy told me o use a paint brush to put it on is that correct ???

Yes, correct. There are videos showing the application (using paintbrush) and buffing of Buff Magic either on http://www.shurhold.com or on http://www.youtube.com . Can't remember where I saw it, but it's easy to find.

 

[jmunro123]

Well I found the Rotary worked better. Did a light wet sand with 1200 grit then, Meguiar's 49 with a Rotary with a white woolpad at low rpm, followed by Pro Polish. Going back tomorrow to make more progress. The rotary however is hard work but faster.

 

[bigblockcutlass]

Last spring I've had a similar situation where my previously use methods (compound/polish/wax) didn't work with prota cable 7424. No matter how much I tried using the orbit with compound it wasn't bringing the shine back to life. So, it was clear that I needed more powerfull tool. So, after reading more on CSR I've purchased Makita Rotary.

What a great tool and pleasure to work with. I've purchased Maguiars #91 Power Cut Compaund and this did the trick to resolve the issue.

In summary my steps were:
1. Makita Rotary with Maguiars #91 Power Cut Compound.
2. Porta Cable 7424 with Meguiars #45 Boat/RV polisher (2 coats are better).
3. Porta Cable 7424 with Meguiars Flagship Wax.

I'm not a fiberglass guru, but before using any type of sanding methods I would try looking in to better power tools with different type of compunds. Just keep in mind that there's a limited amount of gelcoat, so you have to approach it with caution or after 5-7yrs of shiniest boat you'll have no gelcoat layer left.:grin:

Just my .02c.

Do you like the Meguiars 91 over the 49? I plan on doing some work to mine as soon as it warms up. I have two bottles of the 49 with then 45. Plane on using the rotory with wool pad and or foam. Then 56 wax.

 

[jmunro123]

Do you like the Meguiars 91 over the 49? I plan on doing some work to mine as soon as it warms up. I have two bottles of the 49 with then 45. Plane on using the rotory with wool pad and or foam. Then 56 wax.

I did not purchase 91 but looking back that would have been a good idea. Wet sanding does a really good job of making the surface look like it is brand new and super smooth. I did use some heavier marine compound. This experience has taught me a lot. One thing it has taught me is the Mequirs products are superior to getting the job completed as quickly and as professionally as possible. Next year I plan to switching 100% to Meguiars products, I would do it this year but I have so much other stuff it would be a waste. I do have good products, Buff Magic, Pro Polish so there is no immediate rush to change.

I was thinking of using 56 as a final coat- I am not sure my back will hold up tho. If I am up to it I will put 56 over the Pro Polish , maybe that is a mid summer project?