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My rubber cowls look horrible. I have scrubbed them a bit, with no luck. Looks like decades old mold. I will try bleach and TSP. Any other ideas?
Otherwise, if they don't look good I was trying to find a way to paint them. I would imagine most paint would not perform very well on flexible rubber. I see there are paints for Hypolon RIBs. Super expensive. Any ideas for a paint that might work?
I have restored some of mine so they 'almost' look like new!
First step was to get the oxidized dirty looking surface off. Washed off dirt and grime with a detergent or Simple Green or something like that. Even put them in dishwasher! Then tried various things, but I think acetone worked best. (It usually does on vinyl rubrails etc.) I then sanded the surface a bit and painted with a Plastic Paint they sell at Home Depot for painting lawn furniture etc. The one I used is called Rustoleum Specialty Plastic. It requires no primer. It yellows a bit with time, but then you just give it another coat!
By the way, I have used same paint as a cheap gelcoat replacement. For example on a dinghy rudder & centreboard where the gelcoat was badly oxidized. Even on the deck of my boat in small area around anchor locker where gelcoat had yellowed a bit - just blended in a light coat. Can't even see now where it was done.
^^This^^ is what I do. Dampen a rag with some acetone and wipe them clean as new. Use just enough acetone to dampen the rag, no more. Works great for vinyl coated lifelines as well - makes them white as new.
I clean the oxidation off mine with lacquer thinner if they are truly rough/scaberous. if still reasonably smooth acetone works an can be mixed with a bit of water to increase working time.
After trying all kinds of cleaners, I painted mine using rattle can spray paint several years ago. It was flexible and specifically said could be used on plastic and PVC. They have held up great with no pealing or flaking. Don't remember the particular brand, but any decent hardware store should have several choices.
JimsCal, that was to be my next solution having gotten the surfaces as clean snd smooth as possible Valspar makes paint for vinyl and plastics which has the right "coefficient of expansion" to remain uncracked. If yours had held up thats a good sign for this approach
JimsCal, that was to be my next solution having gotten the surfaces as clean snd smooth as possible Valspar makes paint for vinyl and plastics which has the right "coefficient of expansion" to remain uncracked. If yours had held up thats a good sign for this approach
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The Rustoleum paint and preparation quoted above does work well for this type of application and exposure (at least 5 years on some of my cowls) Lacquer thinner can be used instead of acetone. It is/was mostly acetone anyway, but there are now different formulations that may not be as effective. PBBlaster is a penetrating oil for rusted fasteners. Not sure what it exactly contains (mostly naphtha and petroleum oil?) but surprised it would be useful here especially before painting.
In summary - get surface clean with soap and water, clean again with acetone, abrade slightly with sandpaper. Remove sanding residue, spray with Rustoleum special Plastic Paint.
Both JimsCAl and Oysterman23's suggestions will work. Since soft vinyl has a problem in continual release of its 'molding aid' compounds (a corn oil derivative), Id suggest a light first sanding so you get a 'mechanical bond' with the sprayed paint, followed by a 'wipe' with xylene (xylol) followed by another light sanding.
Sometimes, a heavy soak with "PBBlaster", followed by a heavy scrub with a PBBlaster soaked rag will help to remove the oxidized/blackened surface 'molding aid'; and, if that doesn't work - xylene/xylol.
To follow-up. I ended up spray painting them with what was described as , 'for plastic' paint. The two cowls I have are different (previous owner probably lost one). The paint looks fine on both. However, on one it remains tacky. I am going to attach lanyards to keep them from going overboard. Batting .500 on this project.
If you find the 'for plastic' paint starts to crack because it is designed to BOND to plastic, but it is not flexible?
DupliColor makes "bumper paint" and "vinyl paint" that are designed to flex. Available in the larger auto stores. And IIRC Rustoleum and Krylon both make vinyl paints now. There's also one from one of the marine suppliers, designed to recoat MOB covers and fenders, probably only available in white.
Sometimes if paint is being reluctant to dry, you can mist it with "Japan drier" from the hardware store, or something from the auto boy supply, that will help pull off whatever solvents are still hiding in it. With care that it doesn't dissolve the base material itself.
I was reading a post the other day on Facebook, a do it yourself sailing page and a guy had all these tips for using denture cleaner tablets but I guess it's too late you've already painted them.
LMGTFY "There are all kinds of*plastics. If a particular*plastic*bears a close enough similarity toacetone, the*acetone will dissolve*or at least affect its surface, softening, smearing or even dissolving the*plastic. Other*plastics, dissimilar to*acetone,*will*remain unaffected by the solvent."
Google as much as you wish, but I would take actual hands-on practical experience over a Google search any day!
For lifelines, next time mine need replacing, I think I will go with uncoated 1x19 wire. Had that on racing boat I once owned. S/S or Chromed cowls would also look good, but a bit too expensive for me.
Acetone is a solvent and it MAY melt some plastics, not just cleaning the surface but turning it gummy and partly destroying it. Which is why the little metal cans of "industrial strength" goof off (?) warn that they should not be used on plastics without trying them first.
"My cowls and lifelines get sticky without painting!"
Dirty old secret: Plastics, all flexible plastics, have volatile "plasticizers" in them. If the plastic is not cured properly, if it is not formulated properly, if some cheapass has been trying to cheat on the product? The plasticizer bleeds out sooner rather than later, and the plastic becomes gummy. Solvent cleaning can take off the gum--but more soon bleeds through. The only real solution is TRASH IT and replace it with a better brand name product.
Sorry to be the bearer of bads news, but that's just the way plastic are.
The only real solution is TRASH IT and replace it with a better brand name product.
Sorry to be the bearer of bads news, but that's just the way plastic are.
What brand would you recommend as an improvement over Nicro-Fico cowls? Are they made from inferior plastic? Lifelines and tops of fenders are also sticky - I guess they must also be made from inferior materials? :laugher:laugher
However, you are right that plastics like the PVC that many cowls are made from do contain plasticizers that can and do sometimes exude from the surface. Stickiness could also be a sign of incomplete initial polymerization, but this would more likely show up during manufacture or early on in use (BTW, I worked in plastics industry ) In my case, the stickyness is more than likely contamination from aerosols released by the overflying aircraft engines throttling back as they land. Most of the boats on our dock are similarly affected. It even gets on the decks, but there it just washes off.
Not to worry, a good cleaning with acetone soaked rags will make the cowls etc good as new Been doing that for years!
They're vinyl, not rubber and the best thing to restore them is MEK - methyl ethyl ketone. It's nasty stuff so use chemical resistant gloves, do it outdoors and stay upwind. Scrub them with a rag dampened with MEK - it will soften them a bit temporarily and even blend in small nicks - then wipe them with Armor All or similar.
If that doesn't make them good enough for you then vinyl paint will be it.
However, the products they recommend just don't work on our cowls & lifelines. So I guess we use those ketones anyway! Acetone & MEK are similar chemically. Neither good if left in contact with PVC. Acetone evaporates quickly and if put on with lightly soaked rag, won't do any harm.
I have no idea what plastic any particular cowl was made from. And that's not the only factor, since the continuing effort to find cheaper sources often leads to just that: cheap inferior suppliers from wherever. ICOM found that out a couple of years ago after massive complaints of microphone coiled cord failures in cockpit-mounted radios that became gooey after extensive UV exposure. ICOM did the right thing, eventually. They replaced them all.
I've seen plenty of "foam rubber" that turned into gooey sludge, literally like tar. Or crumbled into dust. And the whole photography business dumped PVC slide pages 25(30?) years ago, when uncured gooey vinyl chlorides were found to be eating valuable originals in "archival" storage.
Cleaning with high end solvents because the underlying plastic is no good? Hey, if it works for you, enjoy it. NF might have agreed that there was a manufacturing defect, but I don't think they'd hear much after you said "I've been wiping them down with aggressive solvents". You never know unless you contact them. Sometimes, like ICOM, they decide their reputation is worth it.
You should only use aggressive solvents as a last resort on sunburned 30 & 40 year old vinyl. If it has a textured, abrasive, stained surface from weathering then do it.
If the alternative is trashing the stuff then MEK will bring it back an amazing amount but it should not be used as a "cleaner" on good but dirty parts.
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