Primer not sticking to inside corner of angle...

[KDOG]

I etched, and alodined my fuel tank mount today and both of those steps went great. I primed the pieces once and let them sit for about 20min to a half hour and went to prime again and as soon as the second coat hit the first coat in the inside corners and a few edges, the paint "spread" and revealed the aluminum. I think I may not be waiting long enough between the coats. And yes, I dried the pieces thoroughly in case your wondering. Anyone have any idea whats going on here?

By the way, thanks to whoever recommended the Eagle One Etching Aluminum Wheel Cleaner for the etching, worked beautifully, it was the best I ever seen bare aluminum...

[scottessex]

Not a problem, glad it worked out.

Sounds like you have some impurities still in the aluminum,ie. water, alodine, oil, or silicone. What kind of primer are you using? and when you dried off the metal did you degrease it before you primed? Lots of times oils and even fingerprints will leave a residue that paint will not adhere to.
Once it is alodined, and dry, try wiping the piece with some rubbing alcohol wipe on wipe off with clean rag, or you can go to your local automotive paint supply house and buy a pre-cleaner, or wax and grease remover, wear gloves so you don't get fingerprints.
What kind of primer? I would use a self-etching epoxy, followed by a coat of epoxy sealer. Please don't use spray can primer unless it is of the highest quality. and still, an epoxy will actually seal out moisture, where an air-dry primer will remain porous.

Or you could try a few light, light being the key here, coats of a marine grade/aircraft grade zinc chromate, followed by some epoxy sealer. Then wet sand with 600 grit wet/dry paper before laying down the ground, or color coat.

[KDOG]

I am using Krylon Contractor Grade spray primer. The weird thing is the diagonals came out great and are hanging up in my shop drying till tommorow when I'll put the paint on, also Krylon Contractor Grade spray paint ( Bright Blue ). I must have not done a good job of getting the water or alodine out of the corner of those pieces. I'll have to sand 'em down and try again. Any other recommendations?

[KDOG]

Are you really that adamant that there is no good can spray primer?

[Victor Duarte]

kdog, i didnt paint alu, but 3 times my old vintage car with some epoxy resin repairs. silicon products can prevent primer to stick, enshure you clean each time with new solvant, take care the best solvants and cleaner can be poison stuff.

[KDOG]

I tried it again and one of the pieces still "spread the paint off". I don't get it. I may have to take scotts advice and go to the auto parts shop and get some good epoxy based primer. My only other question is can I still use the Blue spray paint that I bought on top of the epoxy primer?

[Victor Duarte]

Kdog, why dont you call Wicks ? maybe they are used to that kind of problems.
thanks

[scottessex]

Hmmm, I would try some degreaser and a scotchbrite, clean thoroughly, then apply the primer lighty, let dry, another LIGHT coat, and let dry.

Nothing wrong with the spraycans, just the paint will not have the durability or gloss retention of a good automotive product. It will fade and get chalky, plus it will chip easier. BUT it WILL prevent corrosion.

[KDOG]

Hmmm, maybe I'm putting it on too thick as well. I sleep on it tonite and take another crack at it tommorrow. I'll try REALLY LIGHT coats.... anyway thanks for the help all!!!

[RodneyEndsley]

Kdog, You don't need alodine,eagle one ethcing, or anything else. All you need is hot soapy water (dawn dishwashing liquid) and some scotchbrite pads for cleaning. Ware rubber gloves to keep body oils off the aluminum. Rinse with clean hot water and let dry. Then get some Sherwin Williams automotive
#988 Self Etching Primer (12oz spray cans), your done. Then top coat

good luck Rodney

[KDOG]

Yes, I've been wearing the rubber gloves the whole time in case you are wondering.

You don't think you need the alodine or etching? Why is that? Thats contrary to everything I've been told in here. I can understand the self-etching primer cuz that makes sense.

[KDOG]

I figured out the problem. I was trying to prime the pieces too soon after alodining. After I let them sit all night last night, I got up this morning and tried them again. Perfection. Its the only conclusion there could be. Its the only thing I did differently - let them sit overnight. When I get it done, I'll post pics of course. I put 3 coats primer, 3 light coats of paint. Gorgeous. Thanks for all the help guys...

[scottessex]

I Didn't mean to be dissin' on spray paint, but I have custom painted harleys for years, I tend to over do it when it comes to quality finishes. :) :rolleyes:

[Victor Duarte]

I never used can sprays, always problems with the gas, for smallparts they are fine, but if you have a large surface of if you must re-use the can, that's the problem.
BTW, i found automotive stuff is cheaper, it's worth have a air-painter and a small clean room with heating lamps. and VENTILATORS, i remember the first time i spent one night painting my car, on the mornig i was hearing "police sirens" because of the solvant :D
cheers

[gyropilot]

I figured out the problem. I was trying to prime the pieces too soon after alodining. After I let them sit all night last night, I got up this morning and tried them again. Perfection.
KDOG,

That's exactly the way to do it...

Buff, wash, etch, and Alodyne the parts one evening. Let dry overnight.

Prime the next day. Let dry overnight.

Finish paint the next day. Let dry overnight.

*Possibly* assemble the following day, but I've found it's best to let the paint cure for at least two to four days to harden.

Now this assumes warm / dry weather of course. The paint will take longer to dry and cure in cold / damp weather.

Have fun,

John L.

[KDOG]

Too bad I found out the hard way. But the good thing is I found out on the small angle pieces of the fuel tank mount - easier to work with. Glad it wasn't the mast!!!

[Caribean_gyro]

Use "CANMAR" is a volatile cleaner use on auto paint shops prior to paint. This removes ervy oil and impurities. CLean it throughtly blow air to get into hard places then with a clean rag buff it dry. I use only varyprime or vaspar primer in aluminum.

good primer will stick to almost everything
ChuckP