Plastic Repair and Repainting my 92 VFR750

I recently bought a 92 VFR 750 with moderate cosmetic damage. There are zip ties holding cracks together, scrapes, scratches, and broken tabs. The bike runs like a champ and deserves to look better than it does. Looking at my options, I have found plastics available from 1 company where you have to cut out the light holes yourself as well as paint them. They are also rather pricey. I have decided that for now, I would like to do a paint/repair job myself. I do not expect to be able to fix everything myself; however, I have experience painting houses and am relatively mechanically inclined. I believe with patience, research, and methodic procedure, I can significantly improve the looks of my bike. My goal is to try to keep the project at or below $500. I am happy to take pictures of damage if anybody can give me more specific information. I have painted my dirtbike (which is polypropylene and ridiculously difficult to find filler for) and have a few questions before I start my bike. Here are some of my questions.
Is the plastic on my VFR ABS plastic?
What is the BEST filler to use?
Do I need to sand to bare plastic or just to primer?
What is the coursest sandpaper I can use without damaging the final product or the plastic?
Can I buy or use any type of power sander for the job to speed up the sanding?
Is there a way to fix broken tabs or screw holes?
Should I weld the plastic or use an adhesive?
If I jack up the plastic trying to weld it, can it be salvaged?
What is the best and most cost effective method of welding?

Here is some info on what i've tried on my dirtbike.

My process was to sand to bare plastic with 120 then get the marks out by stepping up to 220,320,400,600,1000
I then plastic welded any spots that were cracked with a cheap soldering iron. I would spot weld to hold in place then create a groove with the soldering iron and try to fill in the groove with the sides. Then I backed the weld with fiberglass mesh and resin. (I feel I completely failed at this as the repair was never strong enough to withstand me bending it). I started with 2 light coats of plastic primer then let it dry. I sanded with 1000 grit and then shot 4 light coats of body color in a cross hatch pattern. I would shoot 2 coats, let dry, then sand with 1000 grit and then spray 2 more without sanding and let dry. Then I shoot 3 coats of clear over the top and buff out any orange peel. I am satisfied with the way it looks for my dirtbike but I want my vfr to shine the best I can. I have found that trying to cheap out in the beginning has cost me in the long run.... Body work and repainting my bike is 800-1000 at a shop. Am I wasting my time? Please critique my process and help me. I realize that I have probably made several mistakes and may come off as a complete idiot. I am willing to accept that in order to learn the mistakes of my ways and make a full fledged attempt at fixing my vfr. Also, any links to where I can buy specific products for this job is much appreciated. Thank you in advance for your advice. I am not claiming to know anything about what I'm doing so please rip it apart.
Frustrated Guy

 

Buy a book and start searching the archives here and on other bike forums aboot paint and bodywork. In one of the rare times here, pix are more than useful showing the damage. Even better than the shiny side alone, the other side too. All kinds of opinions aboot the best way to "weld" ABS and the best magic goo to use. All of them being the best money can buy as long as it's your money..

Just a couple of general observations to start: The paint and primer have to be removed and any fresh repair areas. Using resin and glass cloth to back up a repair of any type on ABS will only hold for awhile. A rough surface is needed for "tooth" using 1000 grit paper is a waste of time. Even 400 is too fine for doing repairs. Fillers are usually "filler primers" . Prime, sand back and repeat as necessary. small nicks and divots can be filled and sanded back using body putty which is not much more than thick lacquer. All kinds of power sanders. My best advice is to hand sand until you get a feel for what you are doing. OEM paint and primer can also be removed using a single edge razor blade in selected areas.

Generally speaking unless your plastic is in a "thousand" pieces it can be fixed.

 

The search option is your friend. And go to youtube also.

ABS glue is mostly acetone. It is commercially available. Yes, there are techniques for heat/soldering gun welding.

A good source of ABS plastic for filler is legos.

Lots of tutorials out there on method. Mostly create V in back and fill with molten ABS plastic until over full and complete penetration.

Create V in front and repeat. Now sand until flush and to at least 600 grit before primer.

After that its all painting.

Larry

 

Search engines are everyone's friend. There are several types of ABS "glue" on the market. What they are mostly are cements that rely on MEK and ABS resin. One other fraction in the general mix is acetone mostly to allow the mix to set up or flash off through rapid evaporation. The major fraction by a significant margin is MEK. The basic hardware store stuff is formulated for plumbing. Formulations of ABS differ too. Legos will work as will model car and aircraft bodies, shaved off ABS pipe and fittings and chunks of the same type fairings that need fixing. See: " ABS plastic cement MSDS".

Expect any joins using what I call pipe dope to dry slowly and cure out even more slowly. This leads to warpage on convoluted fairing parts.

Bottom line? There are better fixes for busted fairings that stuff made up from sewer pipe and cement from a hardware store.

600 grit paper on the substrate before priming? Even the two component "epoxy" primers are formulated as both primers and fillers. This is standard bodywork technique that goes back to Henry Fords original assembly line painting when they were painting those model Ts with brushes using lead based enamel and before Dr. Devillbis (a dentist) invented the spraygun and nitrocellulose lacquer was extracted from gun cotton by our friends at DuPont chemical after WWI

Current painting is done with HVLP equipment that applies the coating in what might be considered large droplets hence High Volume, Low Pressure" . Even then the substrate in this case the primer which IMO, should be applied to the entire fairing exterior can be if sanded smooth using an indicator coat, 600 grit is still too fine. The theory, practice and the correct viscosity and shear rate allow the droplets to coalesce.
Another benefit is that with HVLP is that unlike a conventional cup gun or pot rig that some dudes crank up to 40+ psig, the HVLP rig has a lesser tendency to blow a fairing piece all wet with paint onto the deck.

Don't ask any pro painter how they know this..

Plastic welding using an outside heat source like a soldering iron or a small torch will work most of the time if one is really careful. The plastic welding rigs have dropped in price like crazy for one or more reasons. Older ABS fairings and body parts that go back several years required rods of the same material mix. ie the fairing and other parts were coded and the rods as well.

I find with today's adhesion/cohesion cements that V grooving on the backside of a damage fairing piece is asking for trouble. The shiny side is fine but V grooving both sides especially if joining two separate pieces is a PITA to begin with and unless done perfectly with the proper cement is a weak bond looking for a time to fail. Not a good thing when the bike is painted and ya just paid for that or even spent well over 250 pesos just for paint.

SOS.. Buy a book.

Any time you see any moron painting any car or bike with even primer and is not wearing a respirator, find another source of information because the dude is probably drooling in his oatmeal or his family is asking for money to help out with the diaper service costs. This is aboot the same deal as slamming the hammer on a 180 HP sport bike wearing nothing but a pair of these assless chaps, chaps.

 

opcorn:

Mr. Divillbuss was a dentist huh, interesting.

I see them doing power wheelies in open toe shoes sometimes too. ; )

 

Open toes and high heels.. No HD flipflops as yet. We can only hope..

A much more definintive article on DeVilbiss with one exception where the author using an analogy talks aboot painting (whitewashing walls) with a 4" brush. Whitewash brushes were sometimes six and even twelve inches wide and were crudely made. Whitewash is lime and I hell on natural bristle. Also kind of glossed over was that the original sprayrig by the doc was used to apply anesthetic which could have been the popular and soon to become more popular cocaine hydrochloride and maybe even NO2.

DeVilbiss has some really spiffy equipment lines even to the point of small siphon and HVLP top feeders that if carefully used could apply paint to the toesies of those dudes wearing open toed shoes. One must at all costs remain fashionable these days..

http://www.bodyshopbusiness.com/issue/article.aspx?contentid=4109