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View Full Version : After sandblasting before powdercoating



shortpork
04-07-2016, 8:17 PM
Should i apply some kind of cleanable oil to keep it from rusting and have the powdercoater clean that right before? Or should i just not blast it til its ready to be coated? I ask because I want to weld to the frame. So blast, cover, weld, powdercoat? Or spot grind/weld, and blast before coating?

FredoSNR
04-07-2016, 8:27 PM
Do not powder shit until you are absolutely sure everything fits and is correct. I have made that mistake with a frame that was supposed to be straight, turns out it wasnt and I just took the shops word for it and powdered it before mock up. Had to get it straightened, sandblasted and powdered again. Money and time wasted. Build the bike, then once you are sure everything is 100%, bring it to them for blasting and powder.

shortpork
04-07-2016, 8:34 PM
Yea for sure, that was my plan. Build the bike, tear it down, coat & paint, reassemble.

hhc
04-07-2016, 11:30 PM
Yea for sure, that was my plan. Build the bike, tear it down, coat & paint, reassemble.

just clean up the areas your welding too, get the whole thing blasted once its done before powder, if some one was to bring me something and say they oiled it to avoid rust id have to solvent the whole thing, pre bake then solvent again and in all honesty id proboly blast it again anyhow.

shortpork
04-08-2016, 6:12 AM
Right on, that's kinda what I figured. Thanks for the varification!

None
04-08-2016, 6:13 AM
Yes, you don't say which make but remove any weld splatter - which leads little nibs on the frame - which in turn will break through the powder coats and lead to further corrosion etc. I'd go over, and smooth off, all the welds and tabs to remove any sharp edges, and remove excess.

Some pro chopper builders often took this too far and left welds too thin, but any stock frame is going to pigeon shit welding that can be smoothed off. Some joints could even be brazed or given a light cover pass over to make look better.

Or am I just anal about such attention to detail?

shortpork
04-08-2016, 11:18 AM
Obviously yes, all spatter would be removed. But if they're good welds I say leave em. Its just as much of an art form as any other part of fabrication. No reason to weaken any joints either.

hhc
04-10-2016, 11:03 AM
if you want to smooth the welds, jb weld will take the heat of applying powder coat and can be used as filler.

None
04-11-2016, 3:45 AM
if you want to smooth the welds, jb weld will take the heat of applying powder coat and can be used as filler.

Honest questions ... the paint flows and it does not weap any chemicals or "oiliness"?

You've actually done this?

I wondered about this. It's a lot cheaper and easier than braizing over them.

Dragstews
04-11-2016, 5:38 AM
if you want to smooth the welds, jb weld will take the heat of applying powder coat and can be used as filler.

This stuff works really good for filler too....

http://ecx.images-amazon.com/images/I/51KXijn3jgL._AC_UL320_SR286,320_.jpg

shortpork
04-11-2016, 10:36 AM
Nice I was actually curious about a hi temp filler. This can be used on engine cover plates?

Dragstews
04-11-2016, 12:19 PM
This can be used on engine cover plates?

Yep.....

http://i279.photobucket.com/albums/kk140/dragstews/Camel/IMG_0022-5.jpg

Laid on... ^^

http://i279.photobucket.com/albums/kk140/dragstews/Camel/IMG_0023-5.jpg

Sanded down.. ^^

http://i279.photobucket.com/albums/kk140/dragstews/Camel/IMG_0067-1.jpg

Done deal... ^^

I like to heat harden the Lad-Metal then work it down....
That way when the powder is shot and run through the oven, No screw-ups are seen ....

http://i279.photobucket.com/albums/kk140/dragstews/Camel/IMG_0065-2.jpg

shortpork
04-13-2016, 10:50 AM
Wow looks great dragstew! Good stuff. I like the items you used for propping up the parts as well

boomboomthump
04-13-2016, 11:09 AM
The only thing I'd suggest here and the problem with not blasting the whole frame ahead of time is that you don't have the opportunity to review the frame for any hairline cracks or possible areas that have been butchered and covered by bondo etc.

So my suggestion if you wait until the end is to work out the opportunity to come check out the frame before they proceed with powder coating it.

shortpork
04-21-2016, 6:55 PM
Understand what youre saying boomboom, and definitely will check for cracks but the bike only has 6000 miles and was a one owner bike. He did no chopping so Im pretty confident the frame is solid.

Dragstews
04-21-2016, 7:30 PM
Wow looks great dragstew! Good stuff. I like the items you used for propping up the parts as well

http://saintjohnwellesley.org/wp-content/uploads/2012/05/feed-the-hungry.jpg

hhc
04-22-2016, 10:05 AM
Honest questions ... the paint flows and it does not weap any chemicals or "oiliness"?

You've actually done this?

I wondered about this. It's a lot cheaper and easier than braizing over them.

i have used jb weld as fill, its not gonna flow right in and be perfect your gonna have to sand it but you can get it pretty close with your finger. i prebaked the piece then shot it with powder then re bake and had no problems where the jb weld was. i think the prebake is gonna let it vent whatever gases its gonna vent.

None
04-22-2016, 12:28 PM
I've had problems with simple die castings wearing oil ... you may well be right that cooking it first fixes it.

The guys that do those HTS-2000 fluxless brazing rods for aluminium also do one for iron and steel, the HTS-528 (link) (https://www.aluminumrepair.com/ironsteel-repair/).

I've never used either product but for a purely decorative use like this, I'd suspect it'd work/be safe and certainly require less skill and equipment than bronze brazing. It all looks a little "too good to be true" and sales orientated. The company does not answer tech support questions.

Of course, in auto restoration they used to use hot lead shaping which can make perfect shapes for wet painting. Again, I have no idea how it might work on powder and bake paint.