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Post by stevesemti on Jan 20, 2007 16:53:26 GMT -5
New to the bodywork/painting process here and I want to repaint my tank (actually tank, sidecovers, and fenders). I've read that it's better to leave factory paint on, and prep that (sanding, primer, etc.) than to completely strip. However, there are a few small dents I'd like to fill. Woiuld it be better to completely strip the whole thing? (thinking of a chemical stripper) Strip just the area around the dent? Bondo right over the sanded factory paint? I am open to suggestion! And I love this forum, I read it for fun in my spare time!!
Thanks!
Steve in Portland, Maine
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Post by mashermoto on Jan 20, 2007 18:05:44 GMT -5
Steve, you basically want to prepare a surface that the new paint will adhere. I wouldn't strip the tank. Just sand the entire tank and shoot some primer. As for the dent, sand the area with rough sandpaper and apply some body filler.
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Post by spyug on Jan 20, 2007 18:09:23 GMT -5
Steve,
Bondo on paint is a no no. You stand a chance of lifting the paint resulting in bubbling in the filler showing through your finished coat. Strip her down to metal in those areas you need to fill.
Get to bare metal and fill your dings. Sand down to 600 wet/dry including the bare metal. Wipe with a tack rag ( paint store) and a clean rag dipped in mineral spirits. Let dry and shoot as soon as you can with good quality primer/surfacer ( go to your local auto paint store). Wet sand with 600 and shoot again. Get a few coats down and tack rag and mineral spirit wipe after each. Shoot your top coat (s). For a deep shine, shoot with your colour coat and wet sand ( tack and wipe) and then shoot a couple of coats of clear coat. Finish up with rubbing and polishing compounds and after 6 to 8 weeks a good quality Carnuba wax.
Now if you read all the earlier threads, you will see auto store paint applied by HVLP spray equipment is best but rattle can works too and all colours and clears are available in can from most auto stores.
The secret to good finish is the prep.Good sanding and cleaning of the dust is essential as wekll as "sterile" working conditions. In this weather heat is also an issue. You need about 70 degrees with less than 40% humidity for paint to cure properly so if painting in the garage first take the part inside to warm up to room temp. then heat lamps and or Halogen spots work to help the cure once the paint is shot. Take your time and don't rush any of the steps.
Its not rocket science...slow and steady wins the race.
Hope this helps but p.m. me if you need more help.
Cheers,
Spyug
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Post by tomterrific on Jan 20, 2007 18:16:47 GMT -5
Rightly or wrongly, I have always considered the factory paint as the best surface for new paint to adhere to. I think, it must have lasted this long, it must be tough. The problem you will face may be residual silicone from the waxes used. Dents can be worked out somewhat if you make a tool to reach inside the tank and push the dent out. Use every technique you can find to get the surface as smooth and even as possible before you start the final colour coats as shiney paint shows all imperfections. You have heard preparation is everything? Those guys are right!
Tom Graham
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Post by spyug on Jan 20, 2007 18:41:44 GMT -5
Tom is right about new paint adhering to the existing but there are solvents in the bondo that will cause it to rise/blister .....so no bondo over paint. You need to sand to give the metal "tooth" for the bondo to grab so make sure you do that.
The tendency with painting ( especially as regards novice painters) is to rush...you want to see the finished product. The pros can rush........the amateurs need to take some time. I can't stress it enough. Good prep is best. So what if it takes a week to lay down 3 or 4 coats. The end result will make it well worth it.....trust me.
Go slow and show us what you can do.
Cheers,
Spyug.
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Post by stevesemti on Jan 20, 2007 21:43:01 GMT -5
You guys are awesome! I have been reading through these paint threads and did look long and hard before posting this question. I certainly understand that this will take time...I'm starting the prep work now and hope to have paint on in the spring (my garage isn't heated and it's 11 degrees F out right now...so 70 is aways away). So what I'm gathering is that it's ok to paint over properly prepared factory paint (sanded smooth and such) but where I need to fill I should bring to bare metal. I have brand new guns (not HVLP but a gift so I don't care ;D ) and am doing research (mostly through these threads) to choose the best paint....
Thanks so much! I have been enjoying this site for a few years now and am constantly amazed at the depth of knowledge and the creativity of some of the bikes you guys have come up with....
I will post before and afters (eventually!)
Steve in Portland, Maine
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Post by mashermoto on Jan 20, 2007 23:00:23 GMT -5
Steve, for the few paint jobs I have completed I found the local automotive paint store to be real helpful. I used PPG products. Others are good as well. Just ask the guy at the counter. They are usually guys that do painting on the side and don't mind helping. Take your gas tank in with you and show them what you want to do. If they try to give you greif, tell them thanks for their time and go to another store.
I really like the looks of a base coat/clear coat system, but it is a little harder process to follow. No matter what system you use, two or three layers of clear coat is what really makes your project look awesome.
Good luck.
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Post by spyug on Jan 21, 2007 11:41:36 GMT -5
As masher says, the two part colour/clear makes for an outstanding finish but you can also get paint that comes out really shiny and doesn't need the clearcoat. This would be best for a new guy to master. The thing with auto paints are that they will be two or three parts that you will need to mix. Colour, reducer and hardner usually in a formula of something like 4:1:1.
With these systems, you can get special hardeners that make the paint impervious to gas and that is a good thing. Rattle can clear coats say they are the same but I haven't found one yet.
Using a non HVLP gun you are going to get a lot of paint bounce or over spray so you will need to construct some kind of spray booth to contain the "mist". the downside to this is that a lot of it will land back on your paint job. When it dries it will give the paint a "rough" texture that will need to be buffed out. Try to keep the "inlet" pressure to the gun down as low as you can to lessen this. Most non HVLP guns need 50 to 70+ pounds to push the paint but if you can run it under this it will cut the over spray somewhat but won't eliminate it.
Now immediately after spraying and every time you use the gun, you need to really clean it. Even a little bit of dried paint can render a gun useless. Before you paint pull the gun apart and see how it all goes together. After painting and between coats, load the cup with reducer/thinner ( whatever comes with the paint system) and spray it into an old plastic gallon jug. You want it to come out clean. Make sure it is all out before you add paint for the next coat or it will upset the formula and you may get a bad finish or paint that won't cure. After finished painting strip the gun down and clean all the parts in the reducer. Careful of any rubber o-rings. Make sure they clean up and go back in the right place. Blow off all the cleaner before storing.
One nasty thing with paint guns is that they usually come "Chromed" with lacquer clear coat finish. As soon as you use solvents, this clear coat breaks down and becomes gummy. If you have the time, wire brush it all off.
Equipment cleaning is critical if you want to have the guns function again so don't scrimp on it.
Once you get the hang of it , painting is fun. Enjoy and let your creative side shine through.
Cheers,
Spyug.
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