Welding seams and pin holes

[CMD82]

How critical is it that all pinholes are filled when welding in patch panels? Will primer/filler/paint fill in and protect the metal? The metal is structurally strong, it just has a couple pinholes present. Some are visiable without shining a light through the back side.

Thanks,
Chris

 

[CMD82]

Any help would be appreciated.
Thanks

 

[copasspupil]

Spray with an epoxy primer, use a body filler on it then spray the high build if you are using it, follow it up with epoxy to seal the primers and shoot body color.

 

[Nomis]

How critical is it that all pinholes are filled when welding in patch panels? Will primer/filler/paint fill in and protect the metal?
Thanks,
Chris

I've always taken the time to seal them up - if you don't, you're providing an entry point for moisture to get into the filler material and it will bubble up over time. It's a pain but worth it in the long run IMHO.

 

[CMD82]

Thanks for the input. Danno, I have always read to apply filler to bare metal before priming.

 

[Nomis]

I have always read to apply filler to bare metal before priming.

Agreed, ruff up the metal surface a bit and apply filler, sand, then epoxy or 2k primer, top coat, etc.

 

[copasspupil]

What size are the holes? Truly a larger section probably would be better served by filling it first with a body filler but a few small holes as he writes, IMHO does not make that much of a difference. High build would probably fill it in anyway since you are placing quite a bit of it on anyway.

 

[CMD82]

The holes are pretty small, some of which are not noticeable unless a direct light is directed on the seam. Thanks again for all the reply's.

 

[maximum destruction]

Spray with an epoxy primer, use a body filler on it then spray the high build if you are using it, follow it up with epoxy to seal the primers and shoot body color.

x2 epoxy 1st. puddle it up a little to let it run thru the holes. this will seal any porosity. if u want it purty, apply filler & surfacer primer. if not, run a bead of seam sealer over the seam. u can make this look nice as well if u use tape on each side then drag it with an acid brush & remove tape.

 

[CMD82]

Will cold galvinizing compound or rustbullet achieve the same results?
I have done some researching on the web and have come across articles that state to apply filler to bare metal as it will adhere better than over top of primer.
Thanks

 

[maximum destruction]

if u plan on keeping the rig u always start w/epoxy. the epoxy seals the metal. plastic fillers sweat w/temp. change. anyone who has dabbled w/ bodywork has ground out filler from an old repair & usually u will find surface rust under the filler. surfacer primers are porous & will not stop moisture.for best results, follow this:
1 start w/ clean bare metal
2 spray with epoxy & let cure
3 apply & work filler to desired results
4 apply a surfacer primer to fill light scratches
5 block surfacer primer & re-prime
6 watersand (grit depends on type of paint chosen)
7 once all body repair is completed & prepped for paint u can also use the epoxy for a sealer before paint

 

[CMD82]

Yes I plan on keeping the rig for a while, regardless I do not want to do anything half ass. Currently the rear qrts are just about burned in and are/have been sitting for a few weeks with some pin holes. Hopefully I can get then finished soon. Any concern with it sitting without paint/primer? The truck has been in a garage since taking down to metal.

 

[maximum destruction]

how close to the coast are u? salt air & humidity know no boundaries. as soon as u're done doing the metalwork on a panel, it needs to be sealed, NO EXCEPTIONS!! again, u can use etch primers but be careful to check about putting epoxy over it. i would go w/ southern polyurethane's epoxy. dp sucks since they went lead free.

 

[CMD82]

What would be the proper steps to take next to ensure all the exposed bare metal is prepped properly before epoxy is sprayed, considering some of it has been exposed for months?

 

[maximum destruction]

u first need to decide which epoxy u choose to use. some say to use a cleaning solvent, others say it will affect adhesion. buy it & read the can. each manu. is different. i use southern polyurethanes. on something like u have, i would spray it with metal prep just to kill any light flash rust u may have. the stuff is neat. it's pretty much just phosphoric acid. if the panel has a light film of rust, u can spray it with this & watch it change back to clean metal. the next step sounds absurd but it's necessary. rinse the panel with water. yeh, i know, water on bare metal. wtf!! it needs to be rinsed to neutralize it. just as soon as it's rinsed, hit it with a blower & don't stop until it's completely dry. when u think it's dry, blow it some more. u don't want water running out of a seam in the middle of spraying the epoxy. when u're absolutely sure it's dry, use a surgical blue tackcloth to wipe it down & whatever u do, DO NOT TOUCH IT WITH BARE HANDS!!!! commence to spraying via the directions on the can.
p.s. be sure to clean the gun before it sets up. lol.