How to prep and paint aluminum diamond plate?

T

TRT

Need to paint my truck box body color that is bare aluminum diamond plate. Have SPI epoxy, SPI 2K primer sealer, base and UC left over from truck. Need to know how to prep box before I spray the SPI epoxy.
 
Being that it is diamond plate this is a good place to use an aluminum prep wash. BUT it has to be done a specific way in order to ensure the epoxy has good adhesion to the bare aluminum. If it was not diamond plate the best method would be to sand it with 180 grit , wipe it down with 700 W&G remover then prime it with SPI epoxy. Two coats.
First wash the box with a good detergent like Dawn and warm water. Rinse and let it dry.
The diamond plate complicates the sanding process so use a prep wash like this: Ospho works well too.
I will apply it and let it sit for a while. Normally doesn't take too long. Once you are ready to remove it reapply the prep wash making sure you get the entire box wet with the product. Keep it wet for a few minutes (don't let it dry) then rinse it thoroughly with water. You want to remove any and all traces of the prep wash. Once you have rinsed it, quickly blow it off and proceed to epoxy it. No need for W&G remover as the detergent wash and the acid wash will leave it clean. You need to epoxy it though as soon as you have rinsed it because aluminum oxidizes almost immediately. Plan it out so you can do it all in one session. If you wait any length of time you will need to re-etch it with the prep wash. Use nitrile gloves when handling it to keep it clean.
 
I spent a good while scrubbing these diamond plate corners to get them good enough to install.
Then the guy changed his mind and wanted them painted.

Left Rear Diamond Plate.JPG


Went over them real good with a maroon scotchbrite pad, ran them through the blast cabinet, wiped them with 710.
One coat of reduced epoxy primer and then paint.
Tailgate open seat up.jpg

Red Diamond Plate.jpg


Before picture.
005.jpg


After:
Left Front Quarter View.jpg
 
Thank y'all for the info. I could bead blast it but I think I'll try the etch wash. I will follow them directions to the T
 
i know the etch wash that chris posted will work just fine but if you want to save a few bucks then just goto home depot and get the purple industrial degreaser. comes in spray bottle up to 5 gal. its a sodium hydroxide cleaner. it will etch and clean the aluminum in seconds. its a base not an acid which is faster and more reactive on aluminum. just spray it on, let it foam up everywhere then rinse well with water.
 
i know the etch wash that chris posted will work just fine but if you want to save a few bucks then just goto home depot and get the purple industrial degreaser. comes in spray bottle up to 5 gal. its a sodium hydroxide cleaner. it will etch and clean the aluminum in seconds. its a base not an acid which is faster and more reactive on aluminum. just spray it on, let it foam up everywhere then rinse well with water.

Is this the Zepp brand, blue gallon?
 
yes that is the stuff. you have to remember its sodium hydroxide. the same stuff as oven cleaner. it basically dissolves anything organic. as with any acid or base you need to wear gloves. if you get it on your skin or soak your sock lol, you need to rinse it off. dont let it sit on your hands etc for any length of time. that big 5 gal in the pic, i go though prob 6 of those a year. i use a ton of it for pretty much everything. works good for cleaning burnt on pots and pans. i even clean my shower with it lol. the nice thing about it vs many strong acids though is there arent any nasty fumes
 
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