Aluminium Structur coating 1

[Faroukblachere]

Hello
I’d like to improve our painting process.
We build aluminum structures that we paint, here are our steps:
1- cleaning the structure with dilute acid
2- water rinsing
3- Sanding the structure
4- preheating the structure in the oven
5- Powder of the structure
6- baking
I would like to remove the sanding step because it takes a long time, but if I remove it, the powder doesn’t stick well.
Is there a primer product or layer to reinforce adhesion?
Thank you

 

[TugboatEng]

A stronger acid can etch the aluminum which provides a similar surface to etch. Chromate conversion coatings will also improve adhesion. Aluminum is finicky about being coated.

 

[WKTaylor]

FB...

WHAT ALUMINUM ALLOY/Temper??
Acid etch in-tank?
Do You apply a conversion coating and/or a primer?
What powder process and type powder?
How do You apply powder [dry-spray, electrostatic, bath

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Some Fud-4-Thot... available on-line...

Aluminum Association
AA DAF45 Designation System for Aluminum Finishes
AA C-6 Aluminum and Its Alloys
AA ADM Aluminum Design Manual
AA WATP23 Welding Aluminum: Theory and Practice
AA YL-1 Tempers For Aluminum and Aluminum Alloy Products

MIL-HDBK-132 PROTECTIVE FINISHES FOR METAL AND WOOD SURFACES
MIL-HDBK-509 CLEANING AND TREATMENT OF ALUMINUM PARTS PRIOR TO PAINTING
MIL-HDBK-1223 NONTACTICAL WHEELED VEHICLES - TREATMENT, PAINTING, IDENTIFICATION MARKING AND DATA PLATE STANDARDS

MIL-STD-171 FINISHING OF METAL AND WOOD SURFACES
MIL-STD-1516 UNIFIED CODE FOR COATINGS AND FINISHES FOR DOD MATERIEL

MIL-T-704 TREATMENT AND PAINTING OF MATERIEL

NASA-STD-5008 PROTECTIVE COATING OF CARBON STEEL, STAINLESS STEEL, AND ALUMINUM ON LAUNCH STRUCTURES, FACILITIES, AND GROUND SUPPORT EQUIPMENT

PAINTING STANDARD
USAF T.O. 35-1-3 CORROSION PREVENTION AND CONTROL, CLEANING, PAINTING, AND MARKING OF USAF SUPPORT EQUIPMENT (SE)

Regards, Wil Taylor
o Trust - But Verify!
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation, Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", HBA forum]
o Only fools and charlatans know everything and understand everything." -Anton Chekhov

 

[TugboatEng]

Doh, I just re-read my comment. Acid etching provides a similar surface to mechanical abrading/scuffing is what I meant to say.