How To Use Alumiweld

Three Easy Steps To Do It Yourself Aluminum Repair

Heat the parent metal surface .  Heat the surface, not the "AlumiWeld". 

Apply the "AlumiWeld" to the heated surface. 

*Use Neutral Flame if using Oxy Ac - Keep Flame In Motion - Never Plunge Into Water - Cool Slowly*

Clean aluminum down to bare metal, getting off all dirt, paint, and coatings.  Clealiness is essential for strong permanent joint, only in this case "clean" means metallurgically uncontaminated with ions or free electrons. 

This very thin layer of aluminum oxide is what must be removed.  When you puncture this layer with the above tool, it breaks up into a fine powder and floats to the surface of the puddle.  You can actually see it appear on the surface.  Draw the abrading tool through the puddle several times to remove oxides and promote fusion with the base metal.  A few strokes is usually enough - .004 to .005 deep gives maximum strength. 

Get rid of the oxides barrier by going down through the molten coating and abraiding the oxides away.  A thin layer of insoluable oxide began to form on that surface even before you laid the s.s.  brush down.  As you heated the base metal, oxide formed even more rapidly, but became stretched under tension.  We must get rid of the oxide or no penetration will occur. 

Shown is a motorcycle engine casing repaired with AlumiWeld

Localizing of heat techniques can also be utilized to improve the shape of fillets.  If you are joining two pieces of quite different size, you will, of course, want to apply most of the heat the larger piece so that they both arrive at working temperature at about the same time. 

A short stub can be fused to a new rod with the torch flame if you control temperatures carefully. 
It gets even easier with practice.  The repair will harden in just a few seconds and can be worked immediately.  Do not, however, immerse in water, to speed cooling.  You will find this material quite hard.  It will grind, machine, drill, tap, paint, etc.  Much like mild steel.  Yet, when fused with aluminum it is not brittle unless it is cooled too quickly. 

For most jobs a simple LP gas torch is enough.  The aluminum doesn't care how it gets hot, just so you reach and maintain 730F. If you don't already have a torch, buy the hottest one you can get.  You can always turn the heat down.  Use the general purpose tip.  For heavy pieces you will need a fuel-oxygen torch.  If so, use a large - that's right, large tip with a neutral flame to spread the heat evenly.  Heat with the middle or outer cones of the flame only.  Or, use your kitchen or camp stove to help your propane torch.  A shroud of aspestos paper will reduce heat loss to the cool surrounding air.  Any time you can preheat a large piece of aluminum, you are better off because you won't "lose" heat into the rest of the casting. 

If your first job is on something quite valuable, it would be smart to practice on some scrap ( for about 1 to 2 rods worth) to get the feel for this new method.  This is very important.  Heat control is sometimes tricky. 

T-Joints

For maximum strength, tin both members.  Again, Heat the parts not the "AlumiWeld" and flow AlumiWeld into the intersection.  Run the solid end of the AlumiWeld stick through the molten AlumiWeld to remove any trapped oxide. 

Butt Joints

Ends are beveled at a 45 degree angle, brushed clean with a stainless steel brush and then heated and tinned separately.  After cooling, both pieces are brushed again to remove the oxide layer that has now formed and into final welding position.  Reheat both parts equally and fill in the grove with AlumiWeld, kicking in the weld as you go.  Cool slowly by fanning the hot weld with your propane torch as you gradually move away. 

T-Joints

Lap Joints

Parts can be tinned and slid together while AlumiWeld is molten, or a generous fillet of AlumiWeld can be applied around the edges of the lap joint, make sure of tinning and oxide separation by running the stick through the molten AlumiWeld. 

Metered Joints(Windows, Doors, Screens and Frames)

Make sure material is solidly clamped in place.  A neutral flame is applied over the joint area until AlumiWeld will melt when drawn across the joint.  After tinning, the joint may be built up and finished as desired. 

Stripped Threads

Drill old threads out oversized so when filled with AlumiWeld all drilling and taping will be done in AlumiWeld this will make it easier to work with.  After drilling, heat base metal from bottom of the hole up. Tin the wall of the hole beginning at the bottom and working your way up.  Fill the hole, let cool, drill and tap as needed.