newbe with questions......

[dsacco1013]

I need some questions answered, if anyone would like to try to help me out.

1 If I spray lets say a transmission case and I do not get it all on the first pass, and cure it can I go back and respray, will the powder blend?

2 how much volume will 1lb of powder spray? IE if I were to spray a set of long tube headers will a pound do it?

3 If I were to powder coat an item I couldnt hang, would I finish one side and then do the other side?

Thank you!

[tomg552001]

From my experience, if you miss a spot and catch it before full cure, you can patch it up by spraying that spot. But be reminded if you are not hanging the part, and say turning it over on a oven rack, the powder will get lines from laying against the rack which will just not be nice. Once the powder is fully cured, patching up areas is harder and you will usually have to respray the whole thing for it too look nice and uniform.

As far as how much area powder will cover, it depends on how thick you lay it on and how much you over spray. In my mind its better to order more than you need and be able to finish the job, rather than run out half way through. But to answer a question, a pound might not be enough, so i'd get 2 or even 3.

And as i said before turning over onto cured powder may not be too good. I honestly never have done it so i can not give you a definate answer, but even cured powder is a little soft once warm so i imagine it would blemish it. Instead i'd try to figure out a way to sit it on a rack or home made stand so only non visible areas are touched and blemished.

If i have learned anything from power coating, don't mess up, lol, stripping powder is horrible! Good luck!

[non-stick]

Good job, Tom....that pretty much sums it all up.

Question 1 : if you missed a spot, just sand the rough areas down and then give the entire part a general "once over" with some finer grit paper to scuff and re-shoot. You can do multiple coats of powder and not be afraid of it. The guys here do multiple coats all the time with great success all the time with little to no trauma.

Question 2 : There's quite a bit of surface area in headers believe it or not. Don't let the looks fool you. What you are dealing with is called lineal inches as opposed to a square inch. One inch of "imagined" coating surface on a flat panel is 1" X 1". Now.... 1" lineal of imagined tube (take 1" of tube and split it down the middle and bend it flat) from a 2 1/2" header is actually 7 sq. inches! See how that can be deceiving? Just to be on the safe side, 2Lbs. of powder would be better that 1 in this case. (and cheaper by the pound when you buy it like that might I add)

Question 3 : Generally it's not acceptable to coat one side and then try it on the other when coating and let the finished side touch heated metal. People here do thier best to either hang, or make a jig for the part to get the most coverage in one pass that they can. I don't know if you are referring to your headers or not, but I'd try to take the flat on the collector tube and the flat from the header flange and work something that way. Maybe a piece of threaded rod or something attached to the oven rack and you fix it into position some how? It's going to be trial and error on that one. Find the way that best suits you and what you are comfortable with in handling. There is ALWAYS a way to get from "A" to "B"...it just needs to be discovered

All in all... a lengthy way of saying "yeah....what Tom said", lol. Hope that helps ya bud.....OH! and welcome to the forum ..... Russ

[dsacco1013]

Thanks, Tom and Russ

Also one other question, during the first coat, will the powder "stick to the bare metal and not so much to itself? So if I do a part and see a spot in a blind area or flip it over and see a spot if I spray it then will the powder stick to the metal more than the previous sprayed powder? To give a more uniform finish? Did that make sense?

Thanks!~

[tomg552001]

If im understanding the question, you're asking if powder will stick to powder aswell as powder will stick to metal. It is from my experience, powder that is not fully cured, and than sprayed will be just fine, but cured powder will need to be scuffed up to increase surface area. Once again this is just my experience, im sure someone will give you a more precise answer. Good luck

[Hemi-T]

Most of the powders we use are not good for coating headers. The heat will destroy them. Headers are usually ceramic coated, because ceramic has a much higher heat tolerance. I wouldn't powder coat headers.

Hemi-T

[non-stick]

DOH! I got so involved in the question I didn't even think of that. DO NOT coat headers with the epoxy/poly/TGIC powders.....they'll burn right off. sheesh....don't I feel like a dummy now. Ace of the day award goes to Hemi for actually looking at the question instead of saying how it could be done,lol. Sorry....no. no powder coat headers. Higher-temp silicone based stuff good for near the end of the exhaust...but never the headers.....Thanks Hemi....Russ