To Jim -Powder Coat Large Item

[elkriverfab]

Jim,
I have a question for you.

Being you are in the powder coating business, I was wondering if you would share some info.

I have a customer who wants me to powder coat a couple of gates I am building.

I have powder coated many many many small items but not something this large.

The gates are ( 3 X 5 and 3 X 3)

Built from one inch square tubing (outside edge) with 14 gauge scenes welded in.

They are for a pool area and there are no vertical or horizontal tubing pieces, just an outside edge (per customer).

I am using a double burner infra red heater set up from Columbia coatings and of course a harbor freight style powder gun.

I have had good luck with the gun considering it is a shade tree special.

Could you offer me any tips on doing this and also metal prep?

I am going to be using an outdoor black powder, nothing fancy considering the scenes (per customer).

One thing I have had trouble with in the past is where the sheet metal touches the tubing, lack of coverage sometimes (bare spots in the cracks).

With your experience, is this something I can do and have it look good?

This customer is picky and design time alone was extensive.

Any tips would really help.

Thank you.

[jeeplogic83]

Elkriver, in my experience as a powdercoater and making signs it would be well worth your time and money to bring something like that to a Pro. your infrared system will not get the results you are looking for. If you do want to do it, you will need to blast it down to white metal or wash it with a Iron Phosphate wash and rinse available from CC. a pool environment is harsh the chlorine will eat your gate rapidly if you do not have full coverage or a good bond of the powdercoat. JMO
Good luck

[CPK_Jim]

Well, Jeeplogic is correct your infared curing system is most likely not curing the powder properly. You need to get the substrate (metal) up to the cure temp and hold it there for the required time. The usual is 400 deg. F for 12 min. but some powders are different so be sure to follow the suppliers instructions in that area. 3x3 and 3x5 is not really that big, if you want to do them yourself I would suggest you build an oven that will accommodate that size. If you want some info on building an oven check out http://forum.caswellplating.com/oven-building-forum/.

As far as metal prep goes, SANDBLASTING is the best way to go!!! This gives the powder something to adhere to. I blast all items then blow them off with compressed air. They then go into the oven for a prebake cycle, this dries out any moisture that may be on it and also bakes off any oils. Time for the prebake depends on what the item is and where its been, but id say 10 minutes at 350 should be fine for those gates. After prebake let them cool down to atleast 150 deg. F but you can let them cool all the way to room temp if you wanted. Then spray your powder and bake to cure.

As far as your HF gun. I used one of those for about 6 months because the better guns used to be very expensive and I didnt have the $$ for one. But it was a hair pulling 6mo because that gun has many issues. One being what you describe with having trouble getting the powder to cover in the corners. This is due to the Faraday cage effect. One thing you can to do to help get around this is (you may get a shock with that gun) touch the part with your finger while coating these areas, im not quite sure what this actually does but it works like magic sometimes. Another thing you can try is to spray the part while it is hot about 250F, but be carefull because you can get runs that way, and spray those faraday areas first. But the best advice I can give with that gun is, get rid of it and get a different one, maybe a hypersmooth system.

Anyways, I would recommend that you take it to a pro just because I dont recommend that infrared cure. You should expect to pay about $50- $100 per gate though.....

Let me know if you have any more questions,

Jim

[AnotherDano]

+1 on the above advice. Let a pro handle it.

I'm still stuck with my beginner residential oven and I'm itching for a big one! I see $$$ flying past my shop every time I look at the oven I have.

Touching the Faraday areas is a way to dissipate built-up static charge. When Faraday decides to mess with you, it actually repels the charged powder instead of attracting it. A good ground (from the work piece to the earth; eight feet down) will make life a lot easier for you.

Good luck, and keep us posted!

Dano

[elkriverfab]

I know you guys are right............

Stick with a pro......

I just try to do it all at times........

I have found a guy up the road that does a lot of powder coating and he will do a beter job with curing for sure.

I will say this, powder coating is fun and I sure would like to get a decent oven some day!

Thanks everybody for your advice and I will take it!