aluminium stains on sails

[Paul G]

I have an alloy luff track on my oregon mast, it works well except the oxide? stains the sail with dark greasy looking marks. Any clues on how to clean this stuff off?

[Todd Bradshaw]

The recipe I have for metallic stains says to soak the stained portion in one part oxalic acid to sixteen parts hot water, followed by a very good rinse/washing as the stuff isn't good for you. It may help to some extent, but I really doubt you'll ever get all of it out.

[Paul G]

Todd,

Thanks for that, my sailmaker said pretty much the same. next time its real sailtrack or lacings.

Paul

[Todd Bradshaw]

Maybe slugs?

[John B]

any particular ideas on antifouling Todd. same ?

[Todd Bradshaw]

Gee John, I've never needed anti-fouling on my sails. :D I did turtle my old Hobie 18 a couple of times, but I always got it back up before slime started to grow on the sails.... (though sometimes it was pretty close - not a fun boat to flip back upright).

Assuming you're talking about removing the stuff, I suppose it would depend upon what variety of paint it is. Some of the modified epoxy AF paints could be a real bear to get off since the things which will soften them might also do the same to the resin on the sailcloth (which is generally either melamine or epoxy these days). The same might be true of vinyl anti-fouling paint's or others like VC-17, which have extremely strong, fast evaporating solvents. I suspect that once that stuff dries it's already soaked in far enough that it's never coming out. Ablatives might be easier, though the pigment itself is probably strong enough to leave a stain and the copper content might as well.

Standard procedure would likely be to try to remove the binder (the paint part) first and then treat any remaining metallic residue after the oils, etc. in the paint have been removed. The closest thing to paint on the stain removal list would be the "pitch, tar and varnish" category. They suggest trichloroethylene, naptha, and mineral spirits for pitch and tar and trichloroethylene followed by a 50/50 mix of acetone and amyl acetate (I don't even know what that is). It also says that paint strippers based on alkalis should not be used on Dacron.

[pipefitter]

Greased lightning will take the anodized coating off of aluminum which is actually aluminum oxide and you can use it on fabric so maybe might try something like that or aluminum wheel and mag cleaner.

[Peter Malcolm Jardine]

Dishwasher detergent works well on a lot of stains. It has bleaches and detergents that work only with force of water, so they do a good job on a lot of weird stains. (ie... stains in a porcelain or acrylic sink) Hot water must be used as an activator for them.

[Todd Bradshaw]

Gee, that's a really bad idea. Save yourself several hundred dollars and leave the Cascade in the dishwasher! I'd be very careful just grabbing cleaners from under the sink and putting them on your sails. Sometimes all you need to do is alter the alkaline balance of the cloth and your resistance to UV goes right down the drain with the rinse water. As Captain Pre-Capsize found out last month, even theoretically "professional" sailcleaners can wash the life and shape right out of a fairly new sail if they use the wrong stuff and/or improper methods. Why experiment with unknown household cleaners and develop a do-it-yourself method of ruining your sails?

[Paul G]

Todd,

How and where does one buy oxalic acid.

Thanks

Paul

[Todd Bradshaw]

I think I got my last bottle from a home improvement center. As I remember, it was there because people use it to clean concrete floors.

[Peter Malcolm Jardine]

Deckwash products have oxalic acid in them. The label will tell you.

Dishwasher detergent is mild enough not to take the applied leaf off most dishes. It's liable to be a lot milder than oxalic acid.... but it may not work as a result. ;) Oxalic would be my last resort I think.

Most mild soaps with a little bleach will clean stains in sails.

You have to be careful not to remove the binding chemicals in the cloth. Sails can be re-resined now, but it's not cheap.

The biggest enemy of sails in salt water is ... Salt. A good cleaning with a neutral ph cleaner will ensure that certain dirts are not helped to embed in the cloth.

Just my .02 worth. Your mileage may vary.

[ 07-04-2005, 09:19 PM: Message edited by: Peter Malcolm Jardine ]

[Todd Bradshaw]

It certainly may! Sorry Peter, but what on earth does the fabric in your sail have in common with the leaf on your dishes or the finish on your kitchen sink? If dishwasher detergent is safe for them it should be fine on Dacron fabric??? That may be the kind of logic that you get away with while sparring down in the bilge, but before putting something on a $1,000 mainsail, most folks would be far better off using something that's been shown to do the job and not ruin the sail in the process. As to re-resination, that process has one major flaw in that once they strip the resin off, the cloth which remains is about as stable as a T-shirt. To accurately re-resinate the sail these clowns would have to have a mold to lay it over which would allow it to take it's proper shape before they locked it in by painting it with new resin. They don't have such a mold and you're not going to get the proper shape by laying it flat or hanging it up by the corners. Just ask the Captain what a wonderful job they did getting his sail back into it's proper shape before they painted it white. Right now, they're buying him a new one! Every sail I've seen that's been through that process has come in because it had serious shape problems immediately after the "restoration" and needed re-cutting.

[Peter Malcolm Jardine]

Dacron is pretty tough stuff. but... as I say.. everyone can do whatever they want. I don't aspire to be the top of the heap up here. It's too crowded. ;)

I'm well aware of the composition of sails and the various treatments and repair methods. I always try the mildest fix first. Some don't work. That's a different question. There's also a question of whether you race or just putt around. Lots of folks retire sails that others would find years of use in. Different strokes. I think D/W detergent is milder chemically than oxalic acid.All it contains is soap, some mineral suspending additives, a little bleach (oxyen based to coexist with some of the enzymes, it safer to us and the earth) and some emulsifiers for grease and oil, as well as some for helping rinse the dish. You think this is somehow a big problem. That's okay.

If you have problems with my comments in the bilge take it there. As for my experience, I don't offer it to be any better than anyone elses.... and you don't know what it is anyway.

;)

[ 07-05-2005, 12:23 AM: Message edited by: Peter Malcolm Jardine ]

[Todd Bradshaw]

Yes, the Dacron fiber itself is pretty tough stuff. Unless you heat it above about 400 degrees or hit it with a specific solvent that happens to melt it, you're probably not going to harm or deform it. Unfortunately, this may not be the case for the resins, silicones, UV absorbers, fungicides and mildewcides that are used to turn Dacron fiber into Dacron sailcloth, not to mention the seam tape that's helping hold the sail together or the polyester thread which always seems to be more prone to UV problems than the fabric itself. My bottle of Cascade lists potassium hydroxide and sodium hydroxide as the first two active ingredients, which judging by the way they the stuff will burn your skin, are pretty nasty. I'm not a chemist, but my wife has a PhD. in Chemistry and when I asked her about using dishwasher detergent on sails she said it's way too caustic and far from being the desired neutral pH. Considering that she's helped build better than 50 sails over the past ten or twelve years and has a pretty good handle on the process and materials, if she tells me not to put that stuff on a sail, I'm inclined to believe her.

Perhaps there is a reason why all the sailmaking texts generally stress using mild soap and when they do discuss the use of bleach or other chemicals it's usually a very mild solution (like the 5% oxalic acid I listed above) and a specific few chemicals to be used on specific types of stains. The standard industry "text" on cleaning various types of stains from Dacron sailcloth is information originally published by ICI Fibers. If I suggest a solution for cleaning or stain removal, it will nearly always come straight from that text because it's been proven over the years to be as effective as possible, while doing the least amount of harm to the sailcloth as long as the directions are followed.

Since I build sails for a living, I figure that if I screwed up one of my own sails with chemical home brews, I could probably replace it for 25%-30% of what it would normally sell for, build it in my spare time and once it's done I can deduct the cost of the materials. It would end up being far less than the average Joe would have to spend to replace a damaged sail. Even so, the only things I'll put on my own sails that aren't on the ICI list are, Goo-Gone, dishwashing LIQUID (like Dawn or Joy) and a couple brands of citrus-based spray cleaners which work well on oil stains (like when the sewing machine decides to drip a spot of oil on a half-finished sail). Anything else just doesn't seem to be worth the risk.