Painting aluminum

[fickle1]

Hey guys. I am working on my DIY LED project and came across this aluminum project box that I am planning on using as my housing. I am a wood guy so I have not done much in the way of metal finishing. I am planning on priming and painting with automotive paint. I want to fill in the seams where the box was folded. What should I use for this? Bondo or something like JB Weld? Does bondo and automotive primer bond to aluminum or should I be looking for something else? I want a high gloss black finish as the end result. Thanks.

[pico-reefer]

JB weld would work, just fill and sand untill you get the desired finish, or you can use a tig welder capable of aluminum welding, but i doubt you have one. the paint would be fine

[Kyuss]

Filler will bond to that no problem. For something like that though I'd skip the bondo and use some poly glaze as there isn't much to fill, and you can put a skim coat over the entire exterior. Either route you go, be sure to put some tape on the inside of the little holes on the corners before trying to fill em - the tape will easily come off later.

[fickle1]

Originally Posted by pico-reefer

JB weld would work, just fill and sand untill you get the desired finish, or you can use a tig welder capable of aluminum welding, but i doubt you have one. the paint would be fine

Thanks. You are correct I don't own, nor have I ever used a welder lol.

Originally Posted by Kyuss

Filler will bond to that no problem. For something like that though I'd skip the bondo and use some poly glaze as there isn't much to fill, and you can put a skim coat over the entire exterior. Either route you go, be sure to put some tape on the inside of the little holes on the corners before trying to fill em - the tape will easily come off later.

Thanks. Is this what I am looking for? http://www.autozone.com/autozone/acc...er=167010_0_0_

[Kyuss]

Originally Posted by fickle1

Thanks. Is this what I am looking for? http://www.autozone.com/autozone/acc...er=167010_0_0_

I'd go with something like http://www.amazon.com/gp/product/B000P6WR0A/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B004F7RT26&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0VY9W6MERXQ59KB88H25. Fill the corners, spot-welds, and give the entire exterior a skim coat. Then sand down with a flat board (repeat on any low spots if necessary), then use a high-build primer, and wet-sand (up to at least 400grit wet.) Then you'll be ready for color. It's a bit of work, but black will magnify any defects in the surface. Surface prep is the most important part in getting a good paint finish, especially if you're after that wet "piano black" look.

You might try looking around locally if there are any automotive paint stores for the glaze. It's a 2-part so it'll come with a little tube of hardener. Just be sure to read the glaze for the ratio, it's not too hard to figure out but if anything error on the side of using too little hardener, and mix the glaze up in small batches so you don't end up wasting it because it starts to harden before you get to put in on the hood.

[fickle1]

Originally Posted by Kyuss

I'd go with something like http://www.amazon.com/gp/product/B000P6WR0A/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B004F7RT26&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0VY9W6MERXQ59KB88H25. Fill the corners, spot-welds, and give the entire exterior a skim coat. Then sand down with a flat board (repeat on any low spots if necessary), then use a high-build primer, and wet-sand (up to at least 400grit wet.) Then you'll be ready for color. It's a bit of work, but black will magnify any defects in the surface. Surface prep is the most important part in getting a good paint finish, especially if you're after that wet "piano black" look.

You might try looking around locally if there are any automotive paint stores for the glaze. It's a 2-part so it'll come with a little tube of hardener. Just be sure to read the glaze for the ratio, it's not too hard to figure out but if anything error on the side of using too little hardener, and mix the glaze up in small batches so you don't end up wasting it because it starts to harden before you get to put in on the hood.

How about this? It is a 2 part formula.

http://www.autozone.com/autozone/acc...er=540155_0_0_

Is there any advantage to using a glaze over regular bondo?

[autodave]

I would recommend the Evercoat glaze that Kyuss posted.I have never used the Autozone product,but I have used the Evercoat glaze for many years and is a top notch product.Glaze is a thinner(less build), finer(sands easier) and will feather-edge better than a "Bondo-type" filler

[fickle1]

Originally Posted by autodave

I would recommend the Evercoat glaze that Kyuss posted.I have never used the Autozone product,but I have used the Evercoat glaze for many years and is a top notch product.Glaze is a thinner(less build), finer(sands easier) and will feather-edge better than a "Bondo-type" filler

Thanks for the help. I just don't think I can justify ~$40 to wife after I've already spent 30 for the paint primer and sandpaper lol.

[disc1]

Originally Posted by fickle1

Thanks for the help. I just don't think I can justify ~$40 to wife after I've already spent 30 for the paint primer and sandpaper lol.

It is always easier to ask forgiveness than permission.

EDIT: On second thought, that may be why my fish tank lasted longer than my marriage.

[Kyuss]

Originally Posted by fickle1

Thanks for the help. I just don't think I can justify ~$40 to wife after I've already spent 30 for the paint primer and sandpaper lol.

You should be able to find it in smaller quantities than the 30oz tub I listed as you definitely won't need that much. If you can't find it locally and order it online, I wouldn't count on getting hardener with it so be sure to keep that in mind if you decide to order some. The hardener is only a couple bucks.

EDIT: If money is tight on the project, this would be fine..
https://www.napaonline.com/Catalog/C...006436269&An=0

And you'd need this hardener
https://www.napaonline.com/Catalog/C...006436368&An=0

Should run you about $15 total

[customcolor]

if you where to use paint on the alum...you will need a special primer!!! normal auto primers are designed for steel bodies. Alum is a hole new tiger and has its own rules for body work and painting....i never tapped into it because i didnt want to buy the special primers!

[OregonReefer]

There's always anodizing too. Of course if you went that route you'd have to have it welded *if you wanted to hide those seems)

As a somewhat accomplished welder I would highly recommend against "learning" to TIG weld aluminum on anything you plan on as a finished product... the learning curve for aluminum is fairly high and it's very easy to destroy product

[Kyuss]

Originally Posted by customcolor

if you where to use paint on the alum...you will need a special primer!!! normal auto primers are designed for steel bodies. Alum is a hole new tiger and has its own rules for body work and painting....i never tapped into it because i didnt want to buy the special primers!

Not necessary for a light canopy IMO (ie low-wear item compared to a car hood), especially if he goes the course of glazing the entire thing & blocking it. Either way, it's not going to have stones flying at it at 60+mph

[NanoReefWanabe]

Originally Posted by Kyuss

Not necessary for a light canopy IMO (ie low-wear item compared to a car hood), especially if he goes the course of glazing the entire thing & blocking it. Either way, it's not going to have stones flying at it at 60+mph

i think it is an adhesion issue with aluminum, much like galvanized metal...i think a good wipe down with TSP should etch the surface though...but i am not sure if TSP is the right product for the job...it was just the first metal prep that came to mind.

likely going to want to use high temp gloss paint too...

[killab443]

Sand it with 180 grit and fill with bondo, Make sure you use an etching primer. It actually bites into the metal. I work in a bodyshop and I've used that on raw metal for years. Galvanized is probably the only thing it won't stick to.

[customcolor]

Originally Posted by Kyuss

Not necessary for a light canopy IMO (ie low-wear item compared to a car hood), especially if he goes the course of glazing the entire thing & blocking it. Either way, it's not going to have stones flying at it at 60+mph

even though it will be lite wear..it will still expand and contract every time you run the lights. if the paint is not stuck to it well it will pop over time.