Hello!

I have a 1984 hobie 16 with white hulls. Since I wasn't able to finish my ramp for the boat, it was sitting around in the lake by my house all summer. (A dumb idea I'm sure) So as you can bet, there are some nasty brown stains on my otherwise wonderful boat. I have been scrubing with some bon-ami and a brush to get the grime off. It seems to work alright but it is real hard on my arms. Any suggestions for cleaning these hulls that might take alittle less 'arm power' and maybe might work better?

Thanks!

David

Try FSR, or any fiberglass stain remover. Easy to use, it "bleaches" the stain off.

Caleb

Try Snobol toilet cleaner. It's cheap and all you have to do is wipe it on and walk away for ten minutes (no scrubbing) then rinse. Make sure you have good ventilation (acid in lungs bad). You might want to wear gloves also.

Thanks for the tips, I think I will try and get to west marine and find some FSR. I actually have never heard of snobol, but I will look for it when I go to the hardware/grocery store.

When I do attempt either of these options should I apply something afterwards to protect the hulls? Maybe a wax or something?

I use denture cleaner when cleaning my fiberglass shower. It works great. It should work on a boat just as well.

Most abrasive cleansers will dull the gloss of gelcoat somewhat. Bon Ami is a unique product in that it contains the abrasive feldspar rather than hydrated silica, which is in most other cleansers and toothpaste, so it should be safer than Comet or Ajax, though still not ideal. For the best cleaning and improved gloss, use a good rubbing compound like 3M Microfinishing Compound. Use the liquid version with a rotary buffer and the paste version by hand. An orbital buffer is not suitable for this task.

Jimbo

There's a hull cleaner called MaryKate On and Off. Wonderful stuff. Wear gloves.

I use Oxolic Acid dilluted quite a bit. It is Wood Bleach at Home Depot or some such store. If you use gloves and a sponge all you do is put it on, wait for it to work then wipe it off. If you dilute it right it will take about 5 minutes for the fiberglass to come up to almost new. Rinse it off then use a teflon finish to coat it.

Later,
Dan

The oxalic acid is the key. The cleaner ZUD seems to have the highest concentration in it. You can usually find it at a local grocery store near Comet and others. ON/OFF also works great,but you need to be real careful with the acids.

I'm a little weary of using acid cleaners on gelcoat unless the gelcoat has rust stains. Gelcoat has free silica gel particles and acid will etch and erode these particles leaving the surface excessively porous and succeptible to future staining. Oxalic acid is the best acid for removing rust stains, so if you have rust stains, use a product which contains it. Otherwise I'd stick with a rubbing compound. My work experience is in professional refinishing, including on boats and yachts

Jimbo

Jimbo,

Why is an orbital buffer not suitable for use with rubbing compounds?
Would a handheld electric drill with a bonnet chuck be a suitable alternative to a rotary buffer?

Jerry

Rubbing compounds are designed for a machine with a far more agressive action. Without this scrubbing rotary action, the compound cannot remove any significant amount of material, which is the purpose of rubbing compound. This action is also needed so that the compound 'breaks down' during the buffing process. As the compound abrasives break down into finer and finer pieces, the compound transitions from 'cutting' to polishing. Without this agressive rotary action this just does not happen. The result is poor removal of oxidation and poor surface finish.

Actually, as a professional refinisher I can tell you that orbital buffers are not of much use at all. Before foam pads came along, an orbital buffer was the only way to get a swirl free finish when buffing really soft new finishes like some clearcoats. But with the advent of the foam pad you can get a swirl free finish on all but the very softest finishes with a rotary buffer. Remember that a rotary buffer is like 10X faster than an orbital. For those few times in the shop when we feel like we need an orbital for that final touch, we just use a wool buffing pad on a air DA sander. The DA is much smaller and more nimble than those big electric orbitals anyway.

The caveat is of course that if you are unskilled with a rotary buffer you can screws thing up, even get hurt(I knocked myself out cold with a rotary buffer, once. Yup ) It's about impossible to screw anything up or get hurt with an orbital buffer because they basically don't do much.

I think that's why they got so popular; retailers are not afraid they will get sued since you are unlikely to ruin your finish or whack yourself in the head with an orbital no matter what your skill level, so they began to push them as the latest and greatest thing. Just a new way to sell surplus washing machine motors

IMNSHO

Jimbo

Jimbo,

Thanks for the great info. Very useful.
Is an electric drill a totally unacceptable alternative to a rotary buffer because it runs so much slower or can it be used acceptably in some circumstances?

Jerry

The action is right, ie it is rotary rather than orbital. But the area where the tool is held, the pistol grip, is a bit too far from the pad. This makes this kind of tool very unstable to use as a buffer or sander. A right angle drill would be better but then you might as well go out and buy a buffer.

Jimbo