Painting Fiberglass

[admin]

Paul: I have a fiberglass case that I would like to paint.

It has been cleaned with Armor All.

What preparation is required to remove the Armor All coat prior to painting?

[jwilli]

A blow torch? arf.

[kiramdear]

If I may...

Your local auto body guy can sand or bead blast it for you, and that's the only sure-fire way I know. Silicon lubricants are insidious; some strong solvents and vigorous repeated scrubbing are the other option, I'm sorry to opine.

[doctorwho]

A painter I knew once recommended wiping down something to be painted with turpentine to remove any oils and silicones. I'm not sure that will work with thew silicone(s) in Armor-All.

[kiramdear]

It's really bad if you plan to refinish an item that's been armor-alled. If it's not a heavy buildup some nastier-the-better solvents may be effective. Hand sanding just smears it deeper in I believe. But a light sandblasting removes everything and unifies the surface appearance of the piece also.

But I defer to the Mudge; perhaps he's had some successes where I haven't...

[Darkhollow]

I will certainly defer to Paul for a more detailed answer but I know that Interlux makes a fiberglass wash that removes silicon. Whether or not this is appropriate for your specific application I am not sure, as I imagine it is typically applied to bare fiberglass and gelcoat on boats.

Here is a link to the product: Commonly referred to as Interlux 202 available at any West Marine store I am sure.

http://www.jamestowndistributors.com/us ... o?pid=2327

I can't seem to link the product page at Interlux's website but you can do a search there for 202 and it will come up.

http://www.yachtpaint.com/usa/

Interlux Fiberglass Solvent Wash 202 removes mold release agents, wax, oil and grease from hulls of bare fiberglass boats. It is also effective in removing wax and silicone contamination from painted hull surfaces that are being prepared for repainting with Interspray Finish Coatings. It is essential to use Fiberglass Solvent Wash 202 prior to painting fiberglass gel coats, regardless of their age. Fiberglass Solvent Wash 202 is, in addition, an effective brush cleaner.

[jingle_jangle]

Wow, Peter...this opens up a real can of worms! But, I'll try to go through the process for you.

First off, folks, let's get the terminology straight...

"Silicon" (no "E") is a material used in computer chips and wafers, and old thingies we called "transistors", which replaced even older, bigger, and hotter thingies called "tubes" or "valves" which were used centuries ago to amplify and modify different kinds of electronic signals. "Silicon" (and "silica") is also a generic term for "sand". So, if your wife or girlfriend gets "silicon" implants, take her back ASAP--the doc has put sandbags in her body because, no doubt, he never learned what a difference an "E" makes...

"SiliconE"--with an "E" at the end--is the stuff that's used as a protectant coating, caulking, moldmaking material, and lubricant. This is the stuff you don't want on any surface you're about to paint. Armor-All is a silicone/water emulsion that does more harm than good. It has 100X and more the concentration of silicone found in any no-no car wax out there.

A guitar case, hey? Perhaps one of those premium Canadian hardshell cases...car wax or boat wax is the best for these, never Armor-All (which is a polymeric coating loaded with silicone that will destroy fresh paint jobs in a nanosecond).

First I wonder why you'd want to paint it--is the gel-coat surface scratched beyond repair? If it's not, you can strip the silicone as detailed below, color-sand the gelcoat surface, and simply power-buff it back to life, as Fender does with its Mexican and Indonesian guitar bodies, which are painted with polyester, which is the resin used in manufacturing cases such as the one you've got. Gel-coat (the surface of that case), however, is much more durable than polyester paint. Maybe it's that awful fence-post green color they make those in, thinking that it's a color attractive to humans, and you disagree (as do I).

Sanding or sandblasting will not remove Armor-all from a gel-coat surface. Well, let me qualify that--Hand and machine sanding spreads the silicone around, and creates sanding dust that's saturated with silicone and will contaminate every surface in the vicinity, as well as re-contaminating the original surface. Sandblasting aggressively might remove silicone, but then deposits it in the sandblasting medium, where, again, it will contaminate everything blasted afterwards besides re-contaminating your original surface.

Exotic fiberglas washes are unnecessary, too. This isn't a boat or a fresh, just-popped-from-the-mold fiberglass boat hull. But if the Interlux stuff is similar in formulation to automotive wax and grease remover, then use it if it's available. I have no experience with the Interlux stuff, though, so I can't recommend it.

Silicone and stuff like Armor-All which reside on the surface of an item that's mostly hard and clean (it can be glossy or matte), is removed easiest as follows:

Go to a car body shop supply place and buy a solvent called (generically) "wax and grease remover". It goes under several brand names, depending upon the manufacturer: "Pre-Kleeno" (RM), "Prep-Sol" (DuPont), etc. You definitely want the clear type, as DuPont also makes a paste that's water-based that is awful. Remember: NO PASTES.

Wear rubber gloves and a half-face respirator (not one of those cloth or Tyvek cheapie dust masks--you're more concerned about fumes than dust, and it takes a charcoal canister to remove the fumes from the air you're breathing!), do this outside, over a bunch of newspapers spread on the ground, or over concrete. Your lawn probably wouldn't like this stuff and keep it away from your prized petunias, too. NO SMOKING. Saturate a cloth (yes, cotton, yes, t-shirt is OK, don't waste a good diaper) with the stuff, and wipe down as much of the case as you can with one go (say, one half). IMMEDIATELY take a second dry clean cloth and use it to wipe the stuff off.

You're going to need several cloths, some to saturate, and some to wipe dry. DO NOT let the stuff dry without wiping it. Here's why: The solvent will float the silicone and other impurities away, and they remain on the surface of the microscopically-thin solvent film. Allowing the solvent to evaporate only re-deposits the silicone back onto the surface of the item. This is why you MUST wipe the solvent off while it is still quite wet. Now, you're probably thinking, "how can I be sure that I'm getting off all the silicone? Doesn't wiping it away still allow some of it to re-smear back onto the surface?"

The answer is YES, and this is why you must repeat the wiping process three or four times with clean rags each time. Then, if you want to test how silicone-free the surface is, spray a small area with a can of lacquer and see how the paint lays down. If you get fish-eyes (small craters in the paint), there is still silicone present. Repeat saturating and wiping.

Only once the silicone is 100% gone, should you sand or sandblast to prepare the surface for fresh paint. You cannot paint over shiny fiberglas gel-coat; it will flake off in a jif. And, if I was painting the case, I'd prime it with polyester primer after sanding, to prepare the surface for a nice paint job. Sound like a job for pros? I'd think so--the guys at your local body shop might be able to help you, but please get the Armor-All off before you walk into their shop or you'll make enemies fast!

One more caveat: DON'T think that any other solvent (like turpentine, acetone, mineral spirits, denatured alcohol, or lacquer thinner or enamel reducer) will remove silicone. It won't, and you'll mess things up and waste your time. Turpentine, incidentally, has proven to be one of the nastiest solvents around; it permeates your skin, makes everything smell like a paint factory, is a potent carcinogen, and doesn't work for most purposes of cleaning. Its general-purpose replacement, mineral spirits, isn't exactly friendly to you, your skin, or the environment, and is petrochemical to boot, whereas turps comes from the tar of pine trees. The last time I used turps for thinning paint--back in the '60s--it gave me a headache for three days. Ugh.

Despite all these warnings and specifications, this is an easy job, doesn't have to be messy, and can be done quickly. The rags should be left spread out flat outdoors so the solvent can evaporate; most wax and grease removers will not spontaneously-combust (mineral spirit-soaked rags will, and turps is the worst!), but you want to be safe. DON'T launder the rags until the solvent has completely dried out--they will stink up your washing machine and could cause your clothes dryer to explode.

That's why I said, "can of worms". For most laymen it's a whole lotta trouble. Body shops do it all day long.

[admin]

Thanks Paul. I will put this informatin to good use. As always, I appreciate your detailed response.

[teb]

Many of us who paint boats don't use primer these days over fiberglass. With good one-part enamel (Interlux Brightside, Petit Easypoxy, etc.) primer's only real function is to fill small surface defects. It doesn't make these paints stick any better or last any longer. If the surface has been properly prepared (usually solvent washing followed by sanding up to the 100-120 grit range) there shouldn't be any real defects to fill. For those without spray equipment, these paints will go on surprisingly well with a brush or roller. I use what's called "rolling and tipping" where the paint is applied with a small, thin foam roller, rolled out into a thin, uniform layer and then immediately "tipped-out" - which means you very lightly drag the tip of a soft brush over the surface to knock down any bubbles left from the roller. Thickness control is the key to eliminating drips and sags and the roller allows you to apply thinner layers than a brush would. Even smallish items like hatch covers can usually benefit from using a small roller, simply as a means of controlling paint thickness.

This is one I painted out in my old gravel driveway one summer, using a roller in one hand and the tipping brush in the other and Brightside enamel. When this photo was taken the paint job had already been sitting outside for three years and the boat was getting a spring clean-up before going back out on a mooring. Pretty good paint. My only reservation for something like a guitar case would be that these paints don't tolerate an awful lot of scuffing. That's not a problem on boats, but might be on a case. Sprayed automotive paint might take more abuse.

[jingle_jangle]

Nice hull, dude...thanks for the boat guy's point of view on this, and the education it's given us.

My recommendations reflect my own orientation--to paint with automotive paint, which really goes on best over an automotive polyester or urethane primer (Evercoat Feather-Fill or PPG NCP-280) that's been scuffed with #400 paper.

It comes down to economies of scale vs the visual...to build and finish a perfect America's Cup hull--which looks like a mirror no matter how close you get--can cost hundreds of thousands, most of which is labor. To finish a hull or superstructure of a usable boat which doesn't have to be "state of the art", to an appropriate level of slickness, leaves you with a nice surface, but one which doesn't (and doesn't HAVE to) stand up to close scrutiny, needs to be done affordably.

But a car (or a guitar case) needs a nicer level of finish, in general, because of the closer scrutiny that smaller objects naturally get. In general, the smaller a manufactured object is, the finer the level of finish (or "visual resolution") required to keep it from looking shabby.

Consider two extremes--an ocean cruise ship and an iPod. From a "normal" viewing distance--several hundred feet, more or less, a cruise ship looks fabulous--smooth, sleek, and sculptural. Get within fifty feet, and you begin to see the corrosion under the fresh paint, the rivets, and the need for and results from, continuous upkeep. An iPod is invisible at several hundred feet--its visual domain is six feet down to an inch or two, and it's got to be jewel-like in order not to let down our expectations.

Likewise, the boat hull and guitar case, though built with similar technology and materials, because of their scale, have different levels of surface finish which are appropriate.

[teb]

No, actually they don't. But it is a product of how much energy you want to expend, how much free time you have and where you place your priorities. The method I discribed is being used by some of the best custom boatbuilders and restorers in the world, especially when applying 2-part paints to avoid working in a cloud of poison and needing a space suit with piped-in air. If you wish to go beyond the "raw, as applied" state you can sand and buff it just as you might do with a sprayed finish. Whether brushed, rolled or sprayed, it's just a matter of how far you want to take it, but don't assume that boat finishes are meant to be appreciated only at a distance. Personally, I'm generally satisfied with arm's length for paint and maybe half-an-arm's length for varnish. I'd be satisfied with this quality of roller-applied finish on a guitar case (on this one I used spar varnish over 7.5 oz. fiberglass cloth, over the wood).


if I ever have the time to color-sand a boat I certainly must have something more important that I should be doing, but I know plenty of folks who think differently. One aquaintance built this one and sprayed it (Spar varnish over epoxy resin). I told him I thought it needed a pedestal so that he could keep it in the living room. He still wasn't happy because it had a little bit of orange-peel, so he sanded it and buffed it. I'd certainly take an iPod or a car with a finish that looked this good. For a guitar case, I think I'd actually lean toward taking it to somebody who does that Rhino-Hide truck bed liner and have them spray it. Anyway, this one is one hell of a boat finish, from 30' or 30 mm.

[jingle_jangle]

I think your second sentence says better what I took too many words to attempt to say--and failed.

Spar varnish over epoxy? I would have never recommended that combination in a million years, but apparently it works, or your friend would not have wasted his time.

When I started to restore and build woodie wagons back in the very early 1970s, spar varnish was the ticket (we typically used Man O' War then) and I have seldom had a more frustrating experience than trying to sand and buff out that stuff. Yet attending woodie meets, I found that lots of guys were doing just that. I kept trying, with no success.

I switched to PPG catalyzing clear coat (a precursor to what I use on my guitars now) when I began doing Rolls-Royce and Jaguar woodwork, and although it said "not for use on wood" on the data sheet, I presume that was to keep folks from using it and thinking that it would protect wood against the elements. In car interiors, though, this stuff stood up for (in some instances) over 20 years now and no sign of peeling or any other type of failure of the film. As you well know, car interiors can undergo wide temperature swings.

For my most recent woodie restoration--in 2002--I threw away the book and used conversion varnish for all the exterior trim, sanding and buffing the final coats to a glasslike finish. Six years later it still looks like new.

But, still I wonder: how does one buff out spar varnish? It would make my day to learn this trick.

[Darkhollow]

I used to work at a high end marina in Seattle. Which is why I mentioned Interlux products. I did bright work mostly on all kinds of multi million dollar boats and Yachts. Also was involved in a few hulls, bottom coats and even a criss craft cobra restoration (another story altogether). Like Todd mentioned you can get a really nice finish using the polyurethane enamels on fiberglass just using a roller and a badger brush. Just making sure you brush out the texture with gravity. The stuff flows like you wouldn't believe, and any cross brush strokes will be a sanding nightmare after it dries.

If this is a guitar case, I would agree that a gloss paint surface is probably not the best practical solution. Although you can get a decking non skid polyurethane paint that would hold up better. It has been years for me, so there may be better alternatives nowadays.

Rhino lining would actually be a decent alternative, although the Rhino seems to stay more rubbery where the Line-X seems to be a rougher compound.

Todd, I am very impressed with the hull job on your boat. Especially considering you did it on a gravel driveway.

Also, I have used two part varnishes before, the stuff is lethal. Typically when pieces were added at the very end of a restoration or soon before relaunch of the boat. Where we would use the two part varnish to fill the grain with multiple hot coats in a single day. I don't recommend it but from my experience I never saw it fail. There was one instance where we got a cloudy effect from it but I think the guy didn't properly mix the catalyst.