polishing pads for gelcoat - RO150

[canadamike]

Hello,

I need to polish out some gelcoat on a kayak hull. Not sure which polishing sponge to use with the rubbing compoud. Does anyone have any advice?

Thank you in advance!

Mike

 

[BravoRomeo]

I'll be interested in readings replies here. I just started experimenting with machine polishing my personal airplane, which is a fiberglass (GFRP and CFRP) design with a tough UV-resistant urethane-based paint for a top coat. The existing finish has surface oxidation and some oil contamination.

At present I am using a Mirka CEROS (5" pad by 5mm stroke), Festool buffing pads, and the Festool polishing compounds. In the two underwing and under-belly test patches, the results were phenomenal, going from beat up oxidized paint to a bright white, near-mirror finish surprisingly quick.

Here are the pads and compounds I'm using. Your needs may be different, so take it with a grain of salt. I imagine the results might be even faster with a full size DA polisher or the RO 150. However, I needed something super light and maneuverable, thus trying out the CEROS for this application (lying on my back under the wings pressing upward a 5lb polisher for hours on end didn't sound like fun).

Festool:
493866 6" Fine Sponge (white)
493880 6" Very Fine Sponge (black)
499021 MPA 5000 1-Step Speed Cut Compound
493816 MPA 8000 Polishing Compound

Also:
Rejex paint sealant (by Corrosion-X)
Pad & Microfiber cleaner by Chemical Guys
Microfiber detailing towels by Chemical Guys

I started with a very through cleaning (two bucket method to reduce grit contamination), then using the white fine sponge with the speed cut compound. The next step was polishing compound with the very fine sponge. The final step was hand applying paint sealant. A critical aspect is to prime the sponges with enough compound so you aren't rubbing them dry. Also, it is often recommended to start with the least aggressive steps and see how it goes before getting into heavier cutting.

I found a great thread on this forum on polishing... As well as plenty of information on other web sites such as Autopia, BuffDaddy, AutoGeek, etc. there seem to be many rituals around polishing, some which may even be provable, and some probably not. In the end it all seems to boil down to glorified sanding...

Interestingly, there is a movement afoot to go from 6" pads to 5" pads. I just ordered some 5" microfiber buffing pads to try on the CEROS and see how that goes. I have a suspicion that they should be better matched to the counterweight and all things being equal, 400 watts into 5" is more intense than the same spread out over 6".

I also tried a clay bar on the finish before starting polishing, but it had no detectable effect compared to when I've used clay bars on my cars.

I am no expert in this, but have plenty of experience with manual polishing a la Karate Kid. Wax on. Wax off.

 

[canadamike]

BravoRomeo,

Thanks for the reply. You mentioned a thread on this forum re polishing...would you mind sending me a link?

Your plane isn't a Lancair by chance? I also fly and was involved in building one of these.

Thx Mike

 

[Paul G]

I had no idea Festool offered polishing compound, no mention of it on the festoolusa website when shopping for the RO90   I would have bought both the 5000 and 8000 with my latest order but bought another brand instead not knowing the Festool stuff even existed.

As for your kayak, is it so far gone that it needs rubbing compound? If you're not sure try working without it first and see if the results are good. What wax/polish do you use on a kayak? If it is an abrasive cleaner wax like old turtle wax you may be satisfied just machining that on the surface. If its non abrasive and machining it on isn't good enough try a polish compound before going to rubbing compound. And watch those corners so you don't burn them with the pad, don't ask how I know about that  [embarassed]. I've used cleaner wax successfully on faded gel coat camper shells, but haven't resorted to rubbing compound and would be somewhat concerned about how much finish thickness I'd have to work with.

 

[tbellemare]

There are 4 Festool polishing compounds available in North America:
MPA 5000
MPA 8000
MPA 9000
MPA 11000.

There are also microfiber cloths that they recommend using with their polishing system.

Of course, there are a plethora of polishing options, (sponges, wool bonnets, pads, etc.) for the tools.

Tom

 

[Paul G]

There are 4 Festool polishing compounds available in North America:
MPA 5000
MPA 8000
MPA 9000
MPA 11000.

There are also microfiber cloths that they recommend using with their polishing system.

Of course, there are a plethora of polishing options, (sponges, wool bonnets, pads, etc.) for the tools.

Tom

Dang, 9000 and 11000 aren't even on the FestoolUSA website. Secret menu items are cool at In-N-Out Burger (California folks know what I'm talking about) but not at Festool USA

 

[tbellemare]

I have them but haven't tried them yet. I would presume that they just make the shine more mirror-like.

Tom

 

[Bob Johnson]

Does anyone know what color the festool polishing compounds are. I use Menzerna compounds for  polishing furniture finishes. These are white and when polishing woods with open grain like Mahogany the compound gets into any open pore and makes whitish spots that you can not get out. I need to find black or non-white compounds, 3M does make one but hard to find and only in one grit.

 

[tbellemare]

MPA 5000 - white
MPA 8000 - pink
MPA 9000 - blue
MPA 11000 - gray

Tom

 

[BravoRomeo]

BravoRomeo,

Thanks for the reply. You mentioned a thread on this forum re polishing...would you mind sending me a link?

Your plane isn't a Lancair by chance? I also fly and was involved in building one of these.

Thx Mike

Hi Mike, I own and fly a '95 Diamond DA20 Katana (100 HP ROTAX engine). It is a certified two-place, and one of my favorite modes of transport between the mainland and the San Juan Islands up here. Great little plane... Sleek, fun, and efficient.

Love the looks of the Lancair. Maybe someday I'll get a chance to fly in one!

Here is a great thread on polishing. If you scroll down a bit, you'll find an excellent write up by Dan Clark:
http://festoolownersgroup.com/festool-how-to/ro-150-best-pad-combo-for-car-polishing/

Wow, there are more Festool polishes than I realized!  I need to find out more about that. So far the two I have used are decent performers, though there are lots of good products out there, all with their fans. The Festool pads seem well made.

The Rejex paint sealant I am using is something my mechanic turned me on to. It seals the paint and leaves a very slick, glossy surface. Bug splats just wipe right off like Teflon. It seems to last about six months. A little goes a long way. I would imagine there are comparable products, as well.

--
Geoff

 

[Paul G]

Never heard of RejeX before, seems like something I may try. I've been doing very well with Zaino products on my cars, but always good to discover new stuff.

 

[BravoRomeo]

Also found this informative on polishing techniques. He has some excellent hands-on videos up on YouTube as well.

BuffDaddy: Kevin Brown Method

I'll tell you, one of my favorite aspects of both woodworking and auto detailing is the finishing work. It's just so satisfying to see a finish on wood bring out depth and life, and for a car, shine up and feel incredibly silky to the touch.

As to the OP's question of gelcoat, I have no idea how the detailing process changes, if at all. I would sure take a conservative approach and start with the most minimally invasive products and techniques. I gather gelcoat is not something that is easily repairable if you burn through an edge and expose the fiberglass matrix. I don't know. I must be repairable, as I always see people sanding their glass hull boats at the marina, doing patches, etc. Matching color must be a ball of fun, though.

Everyone I talked to told me my plane was gelcoat and to polish it just like a boat, but it turns out it is primed and painted (thus burning through reveals a dark colored primer, which is a dramatic warning before reaching the gelcoat underneath). Moral of story is to always do your research. One of the first tasks I have is removing all the old sun-baked decals, on which I will carefully try using one of those 3M eraser wheels (in my trusty C15 drill, of course!). Fortunately, an excellent place to try things is under the wing, and the wingtip "go faster stripe" decals wrap all around.

Cheers,
Geoff

 

[canadamike]

Geoff and all the others,

Thanks so much for your helpful input.

I have ordered the Festool pad and one sponge after looking through this thread. I will definitely find a CND source for the products that Geoff suggested.

Just an FYI, gelcoat is just a mix of epoxy with pigments, it is usually applied to boat hulls and high performance airplanes. It is usually applied thicker than automotive paints, so the risk of sand through is less.

Geoff: the Katana's were (and I think still are) built in London, ON, Canada, where I used to live. They are a pleasure to fly, alot smoother than the C152 that I learned on many yrs ago!

Mike