Paint adhesion issue |
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Paint adhesion issue |
DSM |
May 2 2007, 12:36 PM
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#1
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Newbie Group: Members Posts: 29 Joined: 28-April 07 From: NTX Member No.: 7,700 |
OK, I've stripped down to metal, done the required metal bumping, little polyester filler to get it straight. Two coats of self etching primer went on last night.
Today I find the self etching primer blistering off of the bare metal in spots. I'm sure the surface was clean. WTF??? I used a Mar Hyde product that came in a qt can. Did not thin it as it looked pretty thin already. I noticed the place where I bought it don't carry this stuff anymore. Perhaps this is why. Back to sanding... I am wondering what's the order. Self etching primer, filler (build up) primer, epoxy primer then base/clear? Have I got this right? Having a fear of the stuff coming off afterwards now. |
VaccaRabite |
May 2 2007, 12:42 PM
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#2
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
OK, I've stripped down to metal, done the required metal bumping, little polyester filler to get it straight. Two coats of self etching primer went on last night. Today I find the self etching primer blistering off of the bare metal in spots. I'm sure the surface was clean. WTF??? I used a Mar Hyde product that came in a qt can. Did not thin it as it looked pretty thin already. I noticed the place where I bought it don't carry this stuff anymore. Perhaps this is why. Back to sanding... I am wondering what's the order. Self etching primer, filler (build up) primer, epoxy primer then base/clear? Have I got this right? Having a fear of the stuff coming off afterwards now. Are you sure that the metal was clean? Really clean? I jae been wanred the touching bare metal will leave skin oils on the metal which will cause ahesion problems. I got some stuff that Eastwoods sells called "Pre" and it really cleans. Zach |
skline |
May 2 2007, 01:04 PM
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#3
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Born to Drive Group: Members Posts: 7,910 Joined: 26-December 02 From: Costa Mesa, CA Member No.: 17 Region Association: Southern California |
(IMG:style_emoticons/default/agree.gif)
You must have had something on there, the paint should stick if it is clean. I use a product called Pre-cleano or something like that, it is for making sure the metal is really clean and then use a tack cloth to make sure there is no dust on it. Even that, if not done correctly will cause problems, dont rub the body with the tack cloth, only lightly go over the body with it, if you rub too hard, the tacky solution will come off and go on the car. |
mills914/s |
May 2 2007, 01:16 PM
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#4
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Member Group: Members Posts: 253 Joined: 23-December 06 From: Coeur D'Alene... IDAHO Member No.: 7,363 Region Association: Northern California |
Use soap and water then let it dry then some solvent cleaner then wipe with dry dust free cloth then wipe the car down with a cheese cloth. you can not be to carefull.
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John |
May 2 2007, 01:16 PM
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#5
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member? what's a member? Group: Members Posts: 3,393 Joined: 30-January 04 From: Evansville, IN (SIRPCA) Member No.: 1,615 Region Association: None |
I have no experience with the product that you are using, but I would suggest visiting the automotive paint supplier that you bought your material from and ask them WTF?
While I would tend to agree that there must have been something on the metal, I also question the age of the material that you are using. Was it a two part etching primer? Some materials have a shelf life. My suggestion is to use automotive products purchased from an automotive paint supplier (all from the same). Let them know what you are doing and have them suggest a "system" that all works together. If you do it now, it is easier later. You don't want a base that is not compatible with the paint you will be using. good luck with it. |
Twystd1 |
May 2 2007, 02:32 PM
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#6
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You don't want to know... really..... Group: Members Posts: 2,514 Joined: 12-September 04 From: Newport Beach, California Member No.: 2,743 |
Here is a heads up on silicone.
If you ever spray WD40 or most any spray lubricant in the vicinity of your paint work.. YOUR HOSED. Most all of the spray stuff has silicone in it. Even a clothes dryer, whereas you use the little squares of anti-wrinkle has silicone in it. And the dryer wil blow silicone all over hell if the dryers exhaust is in the vicinity of your paint work. In fact using towels that were washed with ordinary clothes detergent has silicone on it. (Except Joy dishwashing detergent or TSP) ANY of this stuff will kill a paint job. As dam near nothing sticks to silicone. I agree with all of the fellas above. More than likely your prep wasn't good enough. So heres a notion for you. Prep a small spot on your car. Bout 1 foot square. BEFORE you use the metal prep. Wash down that area with laquer thinner using a clean white towel. I use REAL TPS (tri sodium phosphate) in the wash machine to clean shop towels. NO Detergent (no residue) So wipe down the clean metal with the laquer thinner till ZERO color (dirt &grime) comes off the towel. Then do the metal prep thing. Then primer & paint. This will give you a test bed to see if it's the material you are using or the the prep isn't correct. I know this sounds kinda anal... Yet when you don't know what the problem is. You have start from a known perfect starting place. Hope this makes sense....... Cheers and good luck. Clayton |
tdgray |
May 2 2007, 02:34 PM
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#7
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Thank God Nemo is not here to see this Group: Members Posts: 9,705 Joined: 5-August 03 From: Akron, OH Member No.: 984 Region Association: None |
Also... make sure that the rags you are using to wipe clean (with the proper pre-cleano like RM 901) have not been washed with any detergent with fabric softener in it.
Fab Softener = silicon = no paint sticky |
Matt Romanowski |
May 2 2007, 02:43 PM
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#8
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Senior Member Group: Members Posts: 878 Joined: 4-January 04 From: Manchester, NH Member No.: 1,507 |
Make sure your air supply is clean too. You should run one of the little orange filters on your gun.
You may never find anything substantial. Every once in a while you get fish eyes for no good reason. Just the way it is.... |
DSM |
May 3 2007, 10:54 AM
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#9
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Newbie Group: Members Posts: 29 Joined: 28-April 07 From: NTX Member No.: 7,700 |
It was degreased, power washed, washed with soap and power rinsed, stripped with a DA, blew the dust off, wiped it down with a clean rag with solvent/cleaner and never touched the surface. I am pretty anal.
Self etching primer was layed on within 1 hr of being bare. Apparently the single stage etching primer is NG. I remember finding all the solids in the bottom, had to stir forever to get it mixed. Next time I'll coat the metal with the cat primer. I may take this stuff back with a "WTF" and see what they say. |
oemexp |
May 3 2007, 11:24 AM
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#10
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Member Group: Members Posts: 70 Joined: 5-June 05 From: Fremont, CA Member No.: 4,204 |
Twystd1 made some good suggestions to look for as an underlying problem. You must use didicated air lines to not have regurged oil from air tools getting into your work. When I restore cars, I always:
1) Etch bare metal 2) Rinse, dry tack cloth etc. 3) Shoot epoxy based sealer on all panels (grips infinitely better than primer and protects the metal from rusting). The only down side is that you have to spray the next stage soon or you have sand it if you wait more than a few hours because the paint won't stick to it after that. 4) perform body work with filler as required over the sealer 5) put on seam sealer as required 6) prep all with scotch brite and shoot sealer over all panels (bodywork should be very close at this point like you think you are done) 7) guide coat a mist of flat black rattle can paint 8) block sand it off to leave low spots and scratches showing 9) spot shoot filling primer only on those spots 10) repeat blocking and filling with primer until it's show quality 11) Seal again 12) shoot color soon after and put on coats as required 13) clear coat 14) wet sand the clear 15) buff It looks like a lot of work and it feel like even more while performing but the results will be worth it. Mark |
DSM |
May 3 2007, 11:33 AM
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#11
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Newbie Group: Members Posts: 29 Joined: 28-April 07 From: NTX Member No.: 7,700 |
Mark, What do you use to etch the metal?
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So.Cal.914 |
May 3 2007, 12:01 PM
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#12
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"...And it has a front trunk too." Group: Members Posts: 6,588 Joined: 15-February 04 From: Low Desert, CA./ Hills of N.J. Member No.: 1,658 Region Association: None |
(IMG:style_emoticons/default/agree.gif) You must have had something on there, the paint should stick if it is clean. I use a product called Pre-cleano or something like that, it is for making sure the metal is really clean and then use a tack cloth to make sure there is no dust on it. Even that, if not done correctly will cause problems, dont rub the body with the tack cloth, only lightly go over the body with it, if you rub too hard, the tacky solution will come off and go on the car. (IMG:style_emoticons/default/agree.gif) |
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