What paint do I use for my commando frame??

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I want to repaint my commando frame after I strip it. What paint do you suggest. I want it black in color. I cannot afford powdercoating but I am a good painter. I refinish guitars mostly with nitrocellulose lacquer which is not suitable for metal. I am not looking for show quality but I want a nice durable gloss finish. Dupont centauri was suggested. Should I prime the frame first if I just leave the original finish and scuff it well?????? The finish on it is original black not in too bad of shape. Can I just sand out the bad spots and not strip it down to the metal before refinishing or do I have to strip it down to the metal??? Thanks for any help.
 

Ron L

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While some powder coat looks very nice, I don't like it for a road bike for a couple reasons. Any threaded holes must be masked and if you don't, running a tap into them leaves a crack for rust to start under the coating. Also if you damage the coating, it cannot be repaired. Harley has chosen powder not for the durability or appearance, but for emission reasons.

I have a frame finished in polyurethane (known as DuPont Imron or PPG Delthane) about 10 years ago that looks nice, but has rock chips on the lower tubes that cannot be repaired without stripping the frame. Also these paints require an air supplied respirator due to isocyanate content.

I think a urethane catalyzed acrylic enamel is the best compromise. Fairly tough, but can be repaired with sanding, priming, and a touch-up gun or airbrush. My buddy still uses acrylic lacquer for ease of repair. His frames always look nice.

I have repaired original paint scratches by sanding it smooth, lacquer primer, sand, and black lacquer. This can easily be sanded and rubbed to a smooth finish and blended. If there is a lot of area to repair or you have the bare frame, I recommend stripping it either with blasting or a chemical strip (local shop charges $60 to chemical strip a frame) and starting over with primer and paint. You will get a better finish and protect those hard to get to areas from future rust.

I am not a good painter, but can get by with painting a frame. I do know paint however as I have 30 years experience as a chemist with a major manufacturer of automotive paints.
 
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Good info Ron.

I am going with a powder coat myself I think. Still undecided but that is the way I'm leaning. The hard part is just picking a colour since the colours available in powder coating now is pretty amazing.

Here is a good link for frame prep:

http://www.oldbritts.com/powder_coating.html
 

Ron L

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Make certain you see a panel of the black your powder coater is going to use. Many powder coated frames I have seen are actually a dark gray. Also not all powders are the same. There are epoxy powders and there are polyester powders. Epoxies have more solvent (gasoline, brake fluid) resistance than polyesters but tend to be a bit more brittle and susceptible to chipping. I won't recommend one type over another, just realize there are differences.

As Fred mentions in his article, let the powder coater do the blasting. Powder does not use a primer coat, so must be coated immediately after blasting. Powder goes on thick, so areas where there is motion required (swingarm pivot, centerstand pivot, etc.) may be a problem when fitting.
 
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My two pence worth;

Like Ron, i prefer the paint vs powder coated for the same reasons, but remember if your going to paint the frame (and the amazing number of bits and pieces that go with it) you will need to be a bloody contortionist with a spray gun to get good coverage into all of the nooks and crannies. the powder coater uses electrostatic attraction and simply fogs the powder on. coverage is usually not an issue unless the frame is dirty oily or rusted. Also the powder coating when blasted and coated by the same shop is faster (no waiting for the primer to harden and no sanding between coats). The poly urethane paint does give the best looking finish but it really doesn't look anything like the original factory finish.

Good luck and remember they are both better than doing nothing, it's just that each one has its plusses and minuses.
:) Scooter
 
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If you're going to use powder, then make sure that you discuss masking with the coaters. My advice on a Commando would be not to let it anywhere near the engine cradle and swinging-arm.

These areas are dimensionally critical and all driving loads go through the rear engine bolts. Even assuming that you get everything fitted out (watch out for the swinging-arm bush to cradle clearances, not just in the bearing thrust areas but also behind because it has to be able to slide into place), the coating will soften when warm and make it next to impossible to keep the rear mountings tight.

My preference is for a two-pack finish.
 
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I hadn't seen that article. It makes good sense. That degree of masking-off is not really necessary with paint, although the bearing seats etc are best masked but paint can be removed with a blade.

I learned the hard way about twenty years ago. I had my frame coated by 'De-corrosion Services' who used to give a Norton Owners Club discount. They put so much powder on that it must've doubled the frame weight !

I never managed to get the engine bolts to stay tight although I never snapped any. My reward was oval holes in the crankcase and a cracked top lug from the hammering effect.

The cure included a new (painted) cradle and fully spiggotted and reamed engine mounts.

If you do go for a painted finish, the only really vulnerable areas are the front iso mount which can be removed for re-finishing and the front cross-tube and that can be touched in without being too visible.
 
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For my money powder coating is not the best for frame refinishing. All things cosidered, I think it's much better to paint rather than powder coat the frame. If the frame is properly prepared; degreased, blasted, etched, primed and painted, you'll have a great looking frame. Use an acrylic enamel with a hardner and it will be quite durable, as well. Not to mention repairing. A little sanding, primer if necessary and you can fix almost any area with an airbrush. Rub it out and you will have an undetectable match. The appearance of a quality black paint job will beat the appearance of black powder coating anytime.
 
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Hey Mark-
Show bike or rider? Show bike-strip, prime, sand-all the usual steps from bare metal. Rider-sand out the rough spots & prime. Give it an overall roughing up with a red Scotchbrite after feather sanding in the primed places. Take some allthread or a big bolt and some fender washers and run 'em through the steering head, sealing up the tube with the fender washers, fashion a loop and secure to the through bolt. Run a long bolt through the top shock mounts. leaving off nuts so you can get the paint in there. connect the long bolt to the loop with a load strap or two after tossing the load strap over a rafter or something similar to hang the frame. You can now tilt the frame any way you like front to rear.
Wipe down good with wax & grease remover and let dry. Tack off with a tack rag.
Go to your local farm store and get a quart of VanSickle black enamel and a bottle of hardener. Should set you back 20 bucks or so.
Mix and get after it with a touch-up gun. Very maneuverable, good coverage.
Clean your gun and stand in awe of your shiny new frame.

HTH

Mike
Kansas, America
 
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:lol: Stove enamelling every time ! the frame will have a glass like finish ,the Suzuki GS on the web site (see URL below) was stove enamelled in 2000 and still looks good as the day it was done.:lol:
 
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frame painting

All things considered including cost powdercoating can't be beat. It cost me $120 to get my frame sandblasted AND powdercoated. By the time you buy automotive paint supplies you can easily spend that much. Also a frame is not too easy to paint and not miss any spots or get runs. Incidentally polyurethane is NOT Imron as someone said. If you go ahead and paint it acrylic enamel with hardener works pretty good. PPG and Dupont both have it.Its not as dangerous as Imron and a lot of painters won't use Imron for that reason.
 

Ron L

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Incidentally polyurethane is NOT Imron as someone said

Excuse me, Bob, but with 30 years developing paint formulations I can unequivocably tell you that Imron is indeed a polyurethane, must be sprayed with an air supplied regulator, and contains isocyanate. Do NOT spray this at home in your garage with a dust mask!

http://pc.dupont.com/Phantom/content/imron-dic.html

Other than that, I agree with what you say, powder coating can be cost effective, although $120 is a better deal than I can get. Paint supplies are getting outrageously expensive. I'm surprised the insurance companies haven't figured out a way to reduce those 50% margins that the refinish guys get. Kind of like the insurance companies have done with healthcare.

The acrylic enamels with hardener (usually a polyurethane additive) are nearly as hard as pure polyurethane and a lot safer. These are now the most popular refinish paints and are used for both single stage and basecoat/clearcoat.
 
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Thanks for the info-that probably explains why when a few year ago I tried to paint some parts with just a respirator and vent fan. I didn't get very far before I had to bail out of there. I was using Delstar with hardener.

While I hopefully have your attention what are the reasons you see clearcoat peeling off.
 

Ron L

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While I hopefully have your attention what are the reasons you see clearcoat peeling off.

If you are referring to the OEM clearcoat failure on cars, it is almost always due to an adhesion failure caused by a chemical reaction with the UV rays of the sun. These OEM clearcoats are almost always waterborne systems. Waterborne clearcoats are in their infancy (well hopefully late stage infancy) and despite accelerated testing are somewhat of a gamble for both automakers and paint suppliers. EPA regulations on VOC (volatile organic solvents) released to the atmosphere during application is the driving force here. These waterborne systems are getting much better, but it is a learning experience for all of us.

There are now waterbased refinish coatings (our brands are Aquabase and Envirobase) that are in their third generation of development. These are usually found in the high volume collision centers that can afford to train technicians in their application and who are in EPA non-attainment air pollution areas where the shear volume of solvent put out by their facility attracts the attention of their local regulatory agencies.

By the way, the UV adhesion problem was corrected in the late '90's and I haven't heard of this problem in occurring lately. It affected not only the clearcoat, but the basecoat as well. My own '93 Grand Cherokee had the basecoat peel off in 6-9 inch strips down to the electrocoat primer. The plant that made that vehicle had one of the first all waterborn lines in the US.

Sorry for the diversion. Now back to our regularly scheduled programming. :oops:
 
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Ron, and again, if you will....

Ron,
Do you have any experience with the PJ1 line of products? W.R.T. the porcelain hard gloss black epoxy, semi gloss black case paint and the Yamaha case paint that is apparently similar to the original Commando case paint. I have been using the black spray cans to paint items smaller than the frame and subframes (and lots of other things that get in the way as well... car parts, whatever...… :roll: )
 

Ron L

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Steve,

I have used the silver case paint and the black for the barrels, but don't have any experience or "professional" information on their epoxy or semi-gloss case paint.

The silver seems to be OK for a rattle can paint. The black is holding up, although I have a set of silver barrels painted many years ago with Rustoleum that are doing just as well.

As always, the preparation is the most important.
 
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