Triple exhaust ports and what they are.

[best]

LOL that's why I asked what sort of adhesion and penetration they were getting on the cylinder.

With a miggy, if the base material is too thick (for the machine), the gun tries to add it too fast (to put enough "heat" in) and you'll get "blobs" of build up with almost no penetration at all You might even be able to grab the "weld" with a pair of pliers and break it back off... double

I would like to see your attempts and seriously wish you luck. I'd like to see it for you just so you can monkey with the extra triple area!

Maybe you know this already about preheating in an oven before you start
welding on aluminum? This will really help with the adhesion and penetration.

 

[sicivicdude]

Maybe you know this already about preheating in an oven before you start
welding on aluminum? This will really help with the adhesion and penetration.

Preheating works quite well to promote adhesion and penetration but its effect is limited in the case of an undersized machine trying to weld on material that doesn't "want it".

 

[slickerthanyou]

Preheating works quite well to promote adhesion and penetration but its effect is limited in the case of an undersized machine trying to weld on material that doesn't "want it".

Not to mention, ya really don't want to heat that up too much or your sleeve could move, IMO!

 

[sicivicdude]

Not to mention, ya really don't want to heat that up too much or your sleeve could move, IMO!

I was going to mention sleeve creep but the engine already gets pretty hot by itself (while running) and I've welded the piss out of a cylinder before with no sleeve creep. I attributed it directly to me being the luckiest white boy alive....

 

[slickerthanyou]

I was going to mention sleeve creep but the engine already gets pretty hot by itself (while running) and I've welded the piss out of a cylinder before with no sleeve creep. I attributed it directly to me being the luckiest white boy alive....

Ya but everything is supported when running....And I have no luck as a white boy!

 

[N8tsNastyBlasty]

my mig is 220v, will fry just about anything, ive got an argon bottle and the aluminum wire. the main tool i lack is the spool gun but i have ways around that. i atribute the lack of adhesion previously to poor surface prep, lack of exp. and learning what makes my welder happy. like anything else once i spend some time on it, ill kick ass or atleast make it work.. so far i havent used it other than dicking around . im currently a student @ the National Center for Aviation Training in Advanced Non Destructive Testing and will be able to preform a multitude of diagnostics on my welds and determine if i suck when im done . Gabe has done most of the practicing and id say sucess rate is near %65 and growing.

 

[sicivicdude]

my mig is 220v, will fry just about anything, ive got an argon bottle and the aluminum wire. the main tool i lack is the spool gun but i have ways around that. i atribute the lack of adhesion previously to poor surface prep, lack of exp. and learning what makes my welder happy. like anything else once i spend some time on it, ill kick ass or atleast make it work.. so far i havent used it other than dicking around . im currently a student @ the National Center for Aviation Training in Advanced Non Destructive Testing and will be able to preform a multitude of diagnostics on my welds and determine if i suck when im done . Gabe has done most of the practicing and id say sucess rate is near %65 and growing.

The problem with adhesion is the base material. Cast aluminum isn't made to be very "user friendly" unfortunately.

The folks who cast things need to be able to reduce cost, increase flowability, and decrease cooling and die time. To that end, they use blends of recycled material and a few additives which do not handle adhesion well at all. The main issue is that the material they add will actually combust or decompose at a lower temperature than the base material. Because they're pour casting, these compounds don't bother the cast process. When you get ready to weld the material you're using an electrical arc to heat the surface of the metal up MUCH hotter than the material got when it was cast.

I've found the best way to handle the cast aluminum is to burr or sand off the top layer of aluminum to remove the oxide layer and then heat the material slowly until the top layer of the aluminum is just below the liquidus temperature and then ready a special allow tig welding rod that melts at a slightly lower temperature than standard cast aluminum. As a tiny bit of heat is applied, the filler rod melts and bonds with the base material. With the good puddle of filler rod on top of the base metal, I can add more heat because the good filler doesn't have a layer of oxide or contamination on the top of it to not conduct the heat as well. Once the filler bonds with the base material, it actually dilutes the contaminates and allows them to "fall" to the bottom of the weld pool. If too much heat is applied to early, the contaminates will "boil" to the surface and create a heat resistant "cap" that will hinder heat transfer and penetration into the base material.. The trick is to boil the contaminates up slowly and allow them to "flash off" of the weld pool just a little at a time. It requires some patience and a steady hand to give the contaminates time to boil up out of the bead slowly.

Once a good solid bead is run with the special alloy, then I can add on top of that using standard 4043 3% silicon filler rod.

The end result of that process is more time.... but also a completely seamless bond of new material and old with no ill mechanical properties or problems with adhesion and penetration.