powder coat or paint 4r70?

[papy]

got the 4r70 stripped down. Original plan was to paint the case (enamel paint of some kind were my thoughts) however i am considering powder coating it.
PROS/CONS from member that have done both? i have read that powder coating could potentially warp the case.

JP

 

[Steve83]

No, powdercoating can't warp it. No, I wouldn't powdercoat a transmission case. I'd use DupliColor Engine Ceramic Clearcoat DE1636 (after thorough sandblasting), or Aluminum Cast Coat DE1650 (after thorough washing or sandblasting).

 

[Yeller]

I don't worry about warping as much as annealing the case making it soft. That happens around 400-450 degrees depending on the aluminum. If they are aware and using a powder that will set at 350 degrees, and will run their oven at 350 degrees I wouldn't have an issue. Painting works well and does hold up with quality materials and prep. A pro for paint is it can be performed after the transmission is assembled and ready for installation. Powder will require it be stripped and assembled afterwards, almost a guarantee it will need touch up. Powder will also be expensive, a transmission will require a lot of prep, there are a lot of surfaces that should not be blasted with media or have paint/powder applied. painting after assembly almost eliminates that risk.

 

[904Bronco]

Paint...

 

[duffymahoney]

If it's 100% apart, then have it vapor honed. If no, then paint it.

 

[Broncobowsher]

Paint. Nobody really sees it with the body on. Just little bits of the edges.
Sandblasting can leave blasting dust the internal passages. Solvent won't flush it.

 

[Shimmy]

definitely agree with paint as mentioned. don't see any powder coating has some benefits, none which i think are that applicable in this case. the cast coating epoxy's work really well

 

[papy]

great feed back-thanks.

paint it is as per my original plan. the case and pan have been degreased, wire wheeled and ready for color. With that in mind, what additional prep should i do to make sure i get a good adhesion? i know paint don't like to stick to aluminum all that well.

it defiantly has some etching from the wire wheel which i assume is good?

JP

 

[Steve83]

The wire marks are only good if you want to see them through the paint. If you're not going to sandblast it (external only), then I'd pressure-wash it using dilute Dawn & PurplePower/SimpleGreen, rinse thoroughly (hot water is best), dry it with heat, and then paint it while it's warm. I've never had a problem with paint sticking to sandblasted Aluminum.

 

[kman67]

Hmm, i had my aluminum Explorer alternator bracket powder coated along with my power steering bracket to match. I think I’ll call my powder coater to ask what temp they bake at.
Kyle

Sent from my iPhone using Tapatalk

 

[Yeller]

Brackets aren’t as big of a deal, they don’t have moving parts using them as a wear point, Transmission cases do. Lots of aluminum gets powder coated successfully every day and is just fine.

I did just buy a set of black aluminum wheels that are painted, not powder coated. The manufacturer is worried enough to void the warranty if they are stripped and powder coated, for most non wear or safety, people will die if this goes bad, it is fine. I can promise there’s enough powder coated aluminum wheels I wouldn’t worry about brackets.

 

[duffymahoney]

Vapor honed is 2x better then paint, if it's fully apart.

 

[BruiserOutdoors]

Add a dorman oil pan with drain plug for easy maintenance!

https://www.summitracing.com/parts/...P5dbEJgm6sGNiS_OlcDW1b36Sf8LvnKhoCuo4QAvD_BwE

 

[Broncobowsher]

trouble with the brackets, the bolt is now squishing a couple layers of plastic. It can shift the bracket alignment and let tight bolts get un-tight leaving you a loose bracket. It could be a super thin coat of plastic and no problem, or they could have been trying to cover a trouble spot and left a thick layer that will creep when in service. Powder coat is not a universal solution. Good in places, but not everyplace.

 

[Steve83]

Hmm, i had my aluminum Explorer alternator bracket powder coated...

I hope you removed ALL the coating (powder OR paint) between the alternator case, the bracket, & the head. There MUST be a continuous conductive path for the alt to work. Electrical grease (NOT dielectric) will keep the surfaces clean & conducting longer.