Treating the weld for flares??????

Mike69T · 04-15-2006, 05:40 AM

About a year ago I welded my first set of rear RS flares on my car. I shortly after painted the car and it looks great. It has actually not seen the road yet as there are some minor things to do before it's ready. Anyway.......I was in the garage yesterday and looked at the car and what do you know.....you can see a little line forming exactly where the weld is. I was wondering how you are suppose to treat the metal before you paint. I think i just self etched the bare metal and painted over that.

Any one have good results share your method!!!
thanks

stormmaster · stormmaster's Garage

typically you will add a skim coat of plastic filler over the area unless you are very good at metal finishing...self etch primer is used as a corrosion inhibitor...over that you should have used a sealer...then a high build sandable primer from there you will block sand to insure there are no imperfections in the substrate...after that you add your final finish of paint...

Mike69T · 04-15-2006, 06:23 AM

Yes i did have to use filler, but i was talking about actually treating the metal. Is there anything you would use from the back side??

hoosierdaddy · 04-15-2006, 06:27 AM

I used POR15 on mine . I don't know if it the right product to use but I've no problems or lines showing thru on mine .

stormmaster · stormmaster's Garage

If you used a filler the only reason a line would be showing is the filler wasnt blocked correctly and or the filler shrunk...its possible moisture got trapped in the filler before sealer was applied

Mike69T · 04-15-2006, 06:49 AM

the line just appeared about a month ago. I wasn't there before

Dennis Kalma · Dennis Kalma's Garage

I was worried about the same effect when I grafted Carrera flares on to my '75...

Only conclusion I could find was to lead the joint, a guy who had a lot of experience with Porsche body work suggested that the crimped drip rail permits a small amount of twist on the chassis under high power/acceleration....and apparently lead is much more flexible and willl tolerate the bending while plastic will crack or deform.

Anyway, did it, it has been 13 years and not a mark.....

Dennis

Allenk · 04-15-2006, 08:25 AM

Did you treat the back side as well? I wonder if you are getting moisture coming in from there. I am about 1/2 way through with welding in SC flares so I'm curious if anyone has an explanation.

jpachard · 04-15-2006, 08:59 AM

How are you guys welding on the flares? THey should be a butt joint so you have no lip. If it has been properly welded and metal finished, you should have no problems.

James

afterburn 549 · 04-15-2006, 10:51 AM

Is a real common problem ! Rust and puss where the weld is ! Happens a lot, 20/20 hind sight. Hammer the weld with a Dolley as you do it...can you hammer it now ?? (relax the metal and seals miniature pin holes) form that pt which is my problem too...seal the back side with POR 15 and the a 2 part sealer to keep moisture out. It might haunt you if you do not strike a deal with the rust now.....dont ask me how I know BTDT

Allenk · 04-15-2006, 11:40 AM

I'm using a butt joint and mig welding all around. I use a halogen light in the dark from both front and back to find any pin holes. I'm sealing front and back with por15 and then and epoxy primer prior to a high build polyester primer.

Mike O'Meara · Mike O'Meara's Garage

I did the same thing, light behind the weld seam to find and weld up any minute holes, then POR15 the backside and epoxy prime the front to seal the scar.