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KiddZimaHater
06-23-2012, 01:19 AM
Can anyone recommend a good filler/epoxy for use on Aluminum?
I need to fill-in some small pits, holes, scratches, dings, etc. in AL, then sand it smooth.
It's purely cosmetic, so there won't be any stress near that area.
Or should I just stick with the good ol' reliable JB Weld?

JRouche
06-23-2012, 01:46 AM
Id go with the JB weld. I havent used it on aluminum, only steel. Prolly some guys that have used it on aluminum though that can add some info.
JR

lakeside53
06-23-2012, 01:56 AM
JB will work fine, but if you want a nice painted surface and it's just small dings, use a product called Metal Glaze (?). It's a very thin putty that's used for car body work after bondo.

CCWKen
06-23-2012, 01:58 AM
Just how "cosmetic" does it have to be? If it has to look like aluminum and be near invisible, I would use one of the aluminum brazing rods. The drawback is that the part repaired needs to be heated. If the part can't be heated, there's one and two-part fillers that contain aluminum powder. Even so, it's not "invisible" and will darken slightly if sanded. I occasionally use the two-part aluminum auto body filler. It's tough and hard but turns to a "steel" color when sanded. So tough, it's actually hard to sand without power tools. :cool:

A little more detail about your project would help narrow the selection.

Mike Burch
06-23-2012, 02:39 AM
It can be a bugger of a job to get anything to stick to aluminium long term.
One trick I've heard of is to rub it down with wet-and-dry sandpaper using liquid epoxy as the wetting agent instead of water. This ensures that the epoxy sticks to the aluminium rather than just to the oxide which normally coats the aluminium's surface within seconds of the its being exposed to the air the sandpaper rubs the oxide off, and the epoxy keeps the air off the aluminium underneath.

SGW
06-23-2012, 09:01 AM
Brownell's sells -- or at least did sell -- aluminum powder to mix with their epoxy to give a metal appearance to the hardened result.

Mike -- that trick of sanding the epoxy into the aluminum (sort of) to get under the surface oxide sounds like a great idea.

gvasale
06-23-2012, 10:11 AM
"Lab Metal" sells an aluminum based filler for aluminum. It tends to be a lot more expensive than JB weld. Check it out.

gwilson
06-23-2012, 10:18 AM
If you seriously need an invisible repair,and have just a few pits,I'd drill and tap small holes into the pits,make threaded plugs from the same type aluminum as possible,screw them in,peen them over and polish out.

No aluminum power based product is going to be invisible: The particles are too large,and in a matrix of epoxy,and they won't age the same as real aluminum.

Boucher
06-23-2012, 11:07 AM
http://www.all-spec.com/products/Devcon/Tapes_and_Adhesives%7CAdhesives%7CADH-00/?gclid=CPaA9IDD5LACFalgTAodP3L-2w

This stuff works great for many things, but Mr. Wilson is correct.

Dan Dubeau
06-23-2012, 11:13 AM
If you seriously need an invisible repair,and have just a few pits,I'd drill and tap small holes into the pits,make threaded plugs from the same type aluminum as possible,screw them in,peen them over and polish out.

No aluminum power based product is going to be invisible: The particles are too large,and in a matrix of epoxy,and they won't age the same as real aluminum.

We use aluminum wood screws at work much the same way. Drill a hole, squirt some loctite in, and wind the screw in. Cut it off just proud of the surface, and peen it over, then file/sand it in. It blends right in, and you cant even tell.

We also use a plumbers putty (can't think of the name right now) it's a two part epoxy that you kneed together until uniform, then press into the surface. I always rough up the area with sand paper first, and also use a center punch all around the bonding area to give it something to bite into. The repaired area WILL look different and stand out from the aluminum, but a little testors aluminum paint will make it blend in.

It all depends on just how cosmetic, and structural the repair needs to be. Building up with tig is another option we use once in a while, but again it's all case dependant.

davidh
06-23-2012, 11:16 AM
"Lab Metal" sells an aluminum based filler for aluminum. It tends to be a lot more expensive than JB weld. Check it out.


very good stuff. . . .

vpt
06-23-2012, 12:16 PM
Yup, all kinds of ways to fill voids, pits, and pockets when just cosmetic.

But like others mention it all depends what kind of "cosmetic" it is depends on what kind of filler to use.

DICKEYBIRD
06-23-2012, 12:54 PM
One trick I've heard of is to rub it down with wet-and-dry sandpaper using liquid epoxy as the wetting agent instead of water. This ensures that the epoxy sticks to the aluminium rather than just to the oxide which normally coats the aluminium's surface within seconds of the its being exposed to the air the sandpaper rubs the oxide off, and the epoxy keeps the air off the aluminium underneath.Great tip! Do you let the epoxy cure then scuff that up (making sure not to rub through the epoxy film) before putting the filler on?

Arcane
06-23-2012, 03:21 PM
I remember when I was a kid you could buy a tube of aluminum colored "stuff" that was a one part product that could be used to fix stuff much like you'd use two part epoxy. It was a fairly gooey liquid and not prone to running. I can't remember the name of it and the only thing I could find with a quick Google search was this stuff.

http://www.alvinproducts.com/Products/Products.asp?ID=1

kd4gij
06-23-2012, 04:32 PM
I have never used it but this stuff sounds like it will work for you



http://www.amazon.com/16402-QuikSteel-Aluminum-Repair-Reinforced/dp/B002UJ4WVC/ref=sr_1_5?ie=UTF8&qid=1340478940&sr=8-5&keywords=jb+weld+aluminum

Mike Burch
06-24-2012, 05:52 PM
Great tip! Do you let the epoxy cure then scuff that up (making sure not to rub through the epoxy film) before putting the filler on?
Yep, you then carry on as if painting on epoxy rather than painting on aluminium, i.e., roughen it , prime it and topcoat it.