Fixin' a fender-bender

[e30this]

Did you wipe the fender down with de greaser before you sprayed the primer??
I started body work on my car last week. I took all the panels down to bare metal, sanded with 180 before I layed my evercoat z-grip and I noticed in some spots it didnt stick like there was an oil on the metal or something.

[Jand3rson]

I thought I cleaned it pretty well, I used pretty diluted super clean, but something just didn't sit well. It only did it in the spots where I sanded the paint down to get rid of chips and bad spots, it must have been something in the old paint/primer.

I just dropped the fender off at the powdercoaters, they also do media blasting, so they're just going to strip the whole thing down for me, only costing me $20.

[monty]

Hey Josh, there are a few things that could of been the issue.

Properly cleaning is very important.

Putting on primer too wet and putting heat directly to it too close will cause it to wrinkle.

If you have a feather edge (the edge of the old paint) and pile primer on it it will also wrinkle some times. Older paints will sometimes react with newer paints, epoxy's, acrylic urethanes, ect. The key with older paint is to not put the first 1 or 2 coats of primers/sealers on wet. You want to do it dry to kind of create a bridge then go ahead and put the next 2 or 3 coats on medium wet. The time between each coat is very important too, there needs to be enough time for the solvents to evaporate out. If you put 4 heavy wet coats on back to back it takes that much longer for that 1st coat to properly dry if at all.

Also primer isnt made for filling dents, even little one's. Icing is made for little ones. Primer is simply for smoothing.

If you were closer I would fix this for you.

[Jand3rson]

Those all make sense, thanks man. It's getting blasted, so I should have it back Monday.

What should I use to smooth out any irregular spots?

[monty]

Well, since you fender is already off, you should take it to a local automotive supllier like Wesco. They would be able to tell you what to use for the size of your problems. It's hard to tell what your really working with from pictures though. Icing is best for filling minor dents like the size of dimes. I like UPOL brand icing called Dolphin Glaze, its still thin (watery) like it should be, but has a little bit more build than other icings and its a two part product. If you go the icing route make sure the metal is sanded with 80grit and clean so the icing will stick properly. When the icing is dry(30min or so depending on climate) I like to start sanding it with 80grit then finish with 150 or 220. If you finish with 80grit prior to priming over time the primer and paint will shrink up into those sanding scratches and you will see them. Although paint is dry to the touch in a day or so it really takes time to cure.

Also a little trick to doing body work is if you are right handed like me, use your left hand to feel your work. Your dominant hand cant feel the impurities that your oppsite hand can because you use it daily.

Any questions about anything while doing this pm me.

[Jand3rson]

Thanks man, I'll look into that stuff.

[Jand3rson]

Got the fender back from the blasters today, and Andy spent a bit more time hammering out some of the high spots, it's pretty damn straight now. Some icing like Monty said should smooth it right out, then I can primer it.







Since this is bare metal on the exterior now, should I put a quick coat of primer on it before I do any of the filling, so it won't rust?

[atomic]

yes and make sure to wipe it down first with something to kill what would have attracted any moisture since it is bare (alcohol, thinner, etc)...

[e30this]

You can spray a coat of self etching primer over all the bare metal. Make sure you sand back down to bare metal before you lay any bondo.

[E30Idea]

Honestly, your skills amaze me. Not sure why though, I am just impressed.

Not that you asked but another tip is to use a wet rag with mineral spirits or even water over the primer to see if it is straight once you are done and before paint. It will act as a "clear coat" type look for a few (10-20) seconds to allow you to get an idea of how it will turn out.

Excellent work though!

[monty]

Since this is bare metal on the exterior now, should I put a quick coat of primer on it before I do any of the filling, so it won't rust?

It all depends if you are going to work on it right away or not and where the fender will be stored. If you wait a while and keep the fender inside the house you would be ok without coating it. If the fender will be sitting in the garage for a while then yeah you should put something on it. Before you do though, sand the fender down with dome 150 or 220 then clean it. Make sure the primer is metal etch primer too.

[Jand3rson]

Just got a can of self-etch primer and some acetone. I'll clean it really good tomorrow and give it a coat just to seal it up. It's going to be kept in the garage, and I'm not sure when it will be painted, so that will be best.

Monty, I really appreciate all your input, thanks.

[monty]

yeah not a problem

[e30this]

Sand it with 220 then prime it. if you decide to do body work in a area sand to bare metal with 180. Dont use 220-380, etc or the bondo wont stick as well.
Im going through the same process as you and I ask my buddy who sprayed my engine bay for help and info on what to do.

I just got a nice thick coat of primer down to block out. :)

[Jand3rson]

All I have is some 120, can I use that? If not, I guess I've have to go get some 220 tomorrow.