????tig welding cast aluminum

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can someone tell me the best way to weld cast aluminum with my tig, its been a long time since I've done it. wont to make sure i do it right. Its fora 1976 HD primary casing.. HELP
Reply:Originally Posted by blacksmithcan someone tell me the best way to weld cast aluminum with my tig, its been a long time since I've done it. wont to make sure i do it right. Its fora 1976 HD primary casing.. HELP
Reply:Listen to Zap, He is da man!!! I did a primary once. Preheated and had tons of trouble. The most important thing is to have the base material as clean as possible. This is the best advice I can give. Listen to Zap!!
Reply:Ido quite a lot of welding on cast ali ,these are artistic castings rather than auto parts?.the castinggs i weld are usually about 3/16"thick ,if i can, i grind a v ,for a v butt,clean with acetone ,tack ,reclean ,weld by buttering each side then doing a final pass,most of the welds are ground or chased off afterwards .Mark
Reply:some of the aluminium presently being thrashed about,some bronze as well.Mark,p.s ignore the state of the desk,i know where everything is. Attached Images
Reply:Being a long time Harley fancier as well as a hobby welder I've welded some cast aluminum primaries as well as motor mounts, cylinder heads, etc. on older Harleys both for myself and for some of the local independent dealer in my area. . Everything said above about getting the metal clean is of course true. That said, there are some older Harley parts that simply cannot be welded. I say this because some of the parts were sand castings that have been running in oil for 30-35 years now. Clean them as much as you want but the minute you ht them with your TIG torch, the oil will start coming out. It gets hot and then releases itself from the nice little defects in the metal at a proper speed to gum up your tungsten and lens screen if you happen to be using one. This is not true of all primaries....some of them that I've fixed successfully seemed to be die cast and much smoother. Therefore they didn't hold the oil like the sand cast ones. The oil seems not to be a problem on parts that are not subjected to a hot oil bath on a regular basis. For example cylinder head fins and exhaust ports on older HOGS may be welded nicely after a pre-heat since there will be little oil to ruin your work. The older ones are almost pure aluminum as well and they do weld very nicely, The thing to do is try. If you have a good casting with little oil exposure or absorption, you should be OK. Otherwise, you may have difficulties. As I said, some parts will weld and some won't. The older Harleys had many problems with porous aluminum castings. The insides of the older crankcases used to be coated with an orange enamel that was baked on at the factory. This was to fill the blowholes and other imperfections to prevent them from leaking all the way through the case.  Harley is still lhaving this problem to the present day, although to a much lesser extent since they now use precision castings that are less likely to have the blowholes and porosity. Good luck. Last edited by gnm109; 07-14-2006 at 10:19 AM.
Reply:Customers don't want to believe me when i tell them clean is not enough, sanitary is NOT good enough , i want it sterile  ! they say O K . then show up with an oil film on it . I tell them "I'm  NOT in the parts washing business ."  i weld -that's ALL. Good thing i am retired or i'd starve.[SIZE="5"Yardbird"
Reply:Originally Posted by Roy HodgesCustomers don't want to believe me when i tell them clean is not enough, sanitary is NOT good enough , i want it sterile  ! they say O K . then show up with an oil film on it . I tell them "I'm  NOT in the parts washing business ."  i weld -that's ALL. Good thing i am retired or i'd starve.
Reply:Re ??? Tig Welding Cast Aluminum        Cleanliness Is Next To Godliness. Our Welding Is Done Primarily On Castings From .25 To .37 Thick. We Either Grind Or Wire Brush Area Followed By Cleaning With Acetone Or Denatured Alcohol. Do Not Use Compressd Air. Let It Dry Naturally.i Use An Older Miller Sync 250 With Balance Control Set Between 7 And 10 Withn A 25%helium-75%argon Mix.this Gas Mix Helps With The Thicker Parts And On Castings It Will Also Help With Porosity Issues. That Said, Sometimes,in Our Case, No Matter What You Do, Contamination Still Comes Up And You End Up With A Bad Weld. We Then Have To Grind Out All Of The Bad Area And Start Over. Dont Be Discouraged, Its Not As Bad As It Sounds And Not All Welding On Castings Are Frustrating. For Our Application, We Use Alcotec 4043 Rods,. We Wipe The Rods With Acetone.clean,clean,clean. It Would Be Helpful For Your Own Purposes To Know What Base Metal You Are Welding On But That Is Not Always Possible.alcotecs Website Has A Good Chart Compering Base Metal To Filler Rod Selection. 5356 Filler Rod May Also Work For You. It Does Not Work For Us. 5356 Is Recommended For Temps To 150 Deg. Our Molds Operate In The 550-600 Degree Range(oven Temp) I Hope This Is Of Some Help.      Flintlock
Reply:Hey gnm109, Thanks for the info! I can definetly picture that happening since I've got some Harley castings that look like SPONGES to the naked eye!Ever try baking the oil out?Patrick
Reply:Man it was a pain to read your post Flintlock. However nice info bro
Reply:Try Brazing ....see  as one possible solution. You can Braze using your TIG ....just heat work without forming a weld puddle and melt in brazing rod. If it works, Brazing could be as strong as you will need.good luck, Jim
Reply:Originally Posted by Sober_PollockHey gnm109, Thanks for the info! I can definetly picture that happening since I've got some Harley castings that look like SPONGES to the naked eye!Ever try baking the oil out?
Reply:Originally Posted by ArcieTry Brazing ....see  as one possible solution. You can Braze using your TIG ....just heat work without forming a weld puddle and melt in brazing rod. If it works, Brazing could be as strong as you will need.good luck, Jim