Welding aluminum

[ReAX222]

My dad broke his weight belt mold making ingots for me, so I need another mold. I really like 1-2 lbs ingots for my pot, but I think he would like something with a hole in it. I have a mig welder, but I haven't played with it much in the last few years. When I did, I just used flux cored wire.

I think I need a gas (argon?) and aluminum wire. Does anyone weld aluminum and can point me in the right direction?

My two designs are Several pieces of C chanel side by side and a piece of flat stock to hold them together and cap them off. The other is a large say 2x4" piece of C chanel capped at both ends with an aluminum tube sticking up near one end. Typically I see cast pieces so will welded pieces work and will the pipe cause issues releasing?

[rmb721]

First, you should have a spool gun to weld aluminum, because you can not push aluminum wire very far(too soft). There are electric welding rods available for aluminum that work OK. (Certanium, now Cronatron)

If you pour lead around anything straight such as pipe, you will have trouble with release. A mould has to be tapered.

[ReAX222]

Good to know about the aluminum welding, I may let the welding shop tackle that for me.

I'll keep an eye for angled stuff in the scrap bins. I am having pretty good luck with the coke can molds we used last time. We just cut the top off of (I was drinking Mt Dew, dad had miller lite) coke cans and poured the lead right in. We had to destroy the cans to get the lead out and we had to do some drinking to keep up, but I think it's going to turn out for smelting end.

I am recasting all of my big 6-12 lb ingots in to 1 lb ingots right now. Coke cans fit nicely in my lee 20 pot.

[PatMarlin]

Just using any Mig steel welder is tough for alum.

Really need a welder that set up for it like mentioned above. Work has to be clean and also preheated. Need a lot of amps too.

Took me awhile to get the hang of decent MIG aluminum welding.

[DLCTEX]

Do a search and take a look at the ingot molds (steel) made from angle iron and channel. I am in the process of making some from angle iron. 1 1/2 iron with 4 pieces side by side and two pieces turned outward for handles on the ends. 15 degree angle on the ends to help release. Dale

[JSnover]

Aluminum can be tough if you don't weld it very often. Steel is very forgiving. You have your own reasons for choosing aluminum but but steel welds a lot easier....... at least for me it does.

[Lloyd Smale]

Ive allways used a tig welder to do aluminum.

[JSnover]

TiG is nice for aluminum. I've run some really nice beads with it. But if I'm gonna have a bad day in the welding shop it's probably gonna be with aluminum.

[crabo]

If the piece you are going to weld is very thick, you might want to preheat it first.

[twotrees]

6061 and 7075 alum don't like to be welded AT ALL !!! Stick to 2024 and you can do some good work.

Like the others have said Steel for molds works well.

Good Shooting,

TwoTrees

[Onlymenotu]

For a small job you could/can get by with pushing the wire .... as long as you have a shorter lead and keep it straight as possable* but as stated a spool gun is always better* ... no kinks or coils or twist in it.. but doing big jobs like production welding like when i built semi- dump trailers the wire spool was mounted on the machine witch pushed,,,,, and there was a head with motor on it that pulled together... this being said we were running 20 to 30 foot leads and it was antifreeze cooled... as the point between welding and slumping is not far apart new Alum can be weld reasonably well... old, used, was- is a bear to weld.....you just can't seem to get it clean enuff.... Alum is- reminds alot of welding brass the puddle has the same look and feel* <-- guess is the word* to it workablility to it,,,,, as others have stated...... go steel it welds eazyer is cheaper and tuffer only down fall is weight...but your working with lead anyway he he what is a xta lbs or 2:roll:[smilie=1:

[schutzen]

Steel for the ingot molds and a replacment weight mold for your Dad. The two will be cheaper than setting up to weld AL.

Weight Mold source: Li'L Mac Molds
PO Box 6325, Spokane, WA 99217-0905

[MtGun44]

In my experience, 7075 and 2024 are difficult to impossible to weld and
6061 welds as easy as can be.

Bill

[mauser1959]

Has anyone tried the heat welding rods that they sell at ace for welding aluminum. I saw a guy at a gun show weld a al can and it would tough as nails, but I do not know how deep it will weld.

[ReAX222]

Does lil mac have a website? 10lb molds seem to be in $60 range from retail dive suppliers and my dad isn't setup as a wholesaler anymore. I am unemployed at the moment so cheap is better since we have belts for shot and the cast is for anchors.

The coke cans work great. I melted them all down into 1lb ingots, I have a large ammo box full of 1lb ingots.

[Pavogrande]

Aluminum can be readily welded with a gas torch and Acetylene rich flame. Small tip -
Aluminum should be mechanically cleaned just before welding with a STAINLESS steel wire brush that is either new or not used for any other purpose. Works well for one -off work.
Repaired lots of aircraft engine mounts this way before Heli-arc (TIG) was readily available.

[TxGunfighter]

HeliArc is the best way to weld... But for the cost just buy another mold or make your own... Weld shops have a min charge that will exceed the price of the mold.
TxG:castmine:unfighter

[schutzen]

Lil'Mac web site: http://www.lilmacmolds.com/A-Series_Molds.html

[hotwheelz]

Most of the major points have allready been made but i will add that if your going to use a mig welder on alum. you will need a new liner in the gun, the old one will be way to dirty to push the wire. But if you have an ac/dc buzz box you can run it on the ac side use a scratch start and your welding, without the hi-freq. of a better machine the welds will be dirty and you probably will blow out the start and stoping point just some ideas tho. Good Luck and even if you spend as much as it cost you to get ingot mold on tools your still ahead of the game b/c now you have the tools to do it again or use other places. GO FOR IT!!!!! I would

[Single Shot]

Has anyone tried the heat welding rods that they sell at ace for welding aluminum. I saw a guy at a gun show weld a al can and it would tough as nails, but I do not know how deep it will weld.

I use it all the time to make model airplane mufflers. That is a low temp alloy. It works at 720 degrees F. Too low a melting point for lead casting.

[JIMinPHX]

Aluminum is much easier to Tig than to Mig. Stick is even more difficult. With Tig, you need to get the 100% Tungsten electrode (green stripe) not the 2% stuff (red stripe) & the end of the Tungsten needs to be a ball not a point. You ball the electrode by holding it over a big chunk of grounded copper, then hitting it with high current. Aluminum is welded with AC. If you have balance control, you get to choose the ratio of heat to cleaning. In some cases it is common practice to make a cleaning pass with the electrode first until you see the work surface change finish, then start your actual weld. If you go with a high cleaning ratio, you will be changing your tungsten often. Be very careful not to touch the tungsten to the work. Aluminum loves to jump up & contaminate your electrode much more than steel does. Use pure Argon gas. Use preflow if you have it. Work with a peddle if you have it. Use high frequency if you have it. 40 series wire welds more easily. 50 series wire makes welds that can be plated afterwards.

With Mig, you either need a spool gun (preferred) or a Teflon lined conduit from the machine to the gun (preferably a short one). Here too you use pure argon, not the C25 mix that is commonly used on steel. Mig on AL is a very fussy process. It takes a lot of fine tuning to get the controls set just right. Your technique needs to be just right too. It is very easy to make a bead that looks good, but has no penetration & will rip off the surface of the work easily. Mig on AL is best left for long production jobs, where the speed of the bead laying justifies the long set up time.

Stick on AL is a real pain in the backside. It's very hard to get good results. At a minimum, you need to preheat the work with a torch. Prep work needs to be positively immaculate & even so, you will likely get contamination in the weld when you first start because the burning flux on the outside of the rod doesn’t shield the weld area fast enough when you start. Expect black marks around the bead start. You really need to start your weld on a scrap piece that is next to the work & then transition into the actual workpiece if you want a chance at a clean bead. I do not recommend stick on AL if you have any other option available.

Regardless of your chosen welding process, the material needs to be very clean before you start. You need to pull about twice the amps when welding aluminum compared to welding steel of the same size.