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Case Welding
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Posted by: Tom68---------------------

Any wire suggestions for TIG welding IT465 RH main case and Mag' clutch cover.Starting accident, turns out motor had no base gasket and the silicon they used wasn't fuel resistant plus it's 1.5mm O/size so the comp' was upped by more than .75:1.

Posted by: whenfoxforks-ruled---------------------

Magnesium can be welded? I know it burns well!

Posted by: Ol'89r---------------------

Quote:

Originally Posted by Tom68

Any wire suggestions for TIG welding IT465 RH main case and Mag' clutch cover..

Tom.

I use a 4043 or a 5356 rod on aluminum cases. Prefer 4043 unless it needs to be anodized or heat treated, then use 5356. On mag I use AZ97.

Good luck.

Posted by: Tom68---------------------

Quote:

Originally Posted by whenfoxforks-ruled

Magnesium can be welded? I know it burns well!

Burns in the form of dust or swarf, I weld magnesium wheels. Thanks Ol'89r I'll give it a go as soon as I get the stomache to split it and see what other horrors await.

Posted by: rpm12505---------------------

Quote:

Originally Posted by Ol'89r

Tom.

I use a 4043 or a 5356 rod on aluminum cases. Prefer 4043 unless it needs to be anodized or heat treated, then use 5356. On mag I use AZ97.

Good luck.

Is AZ97 the trick? I've had a hell of a time trying to weld mag or whatever the side cover is on a zook. Gave up and bought an aluminum one, at least I can weld that.

Posted by: Ol'89r---------------------

CORRECTION!

It's AZ92-A rod for mag. Had to look up the invoice from the welding supply.

RPM. The trick is to boil out all of the impurities. Especially in a engine case where oil has been introduced to the mag. You may have to go back over the weld several times until the oil has stopped coming out and the pin holes go away.

Sometimes it helps to grind the contaminated metal away with a rotary file. When you weld up to the good metal, (the original case metal) go over into the good metal a little bit and 'wash' the bead into the good metal. This will help eliminate air bubbles between the weld material and the original case metal. Mag must be kept extremely clean. Even more so than aluminum. Also, the mag rod will oxidize very quickly in storage. Be sure to clean the rod and remove all of the oxidation before welding. A Scotchbright pad works good for this.

Foxforks.

Mag does burn with great intensity. But, it needs oxygen to burn. With a tig welder you use an inert gas (argon) to shield the weld from the atmosphere. If anyone has ever been out in the desert when someone throws an old set of magnesium Volkswagon engine cases into the bomb fire, it will make you very reluctant to weld on mag.

Posted by: Tom68---------------------

Thanks for the impurities warning, I won't freak if the first pass looks like crap.

Posted by: rpm12505---------------------

OL'89R

Thanks for the info on mag welding

I know exactly what your talking about. The few times I've tried welding mag it looked like the surface of the moon after the material I added popped off. Pretty disheartening considering I've been welding aluminum for a while

VW cases in a bon fire

That must have been wild. I was pretty impressed in HS when we lit off those little strips in science class.

Posted by: whenfoxforks-ruled---------------------

I remember a guy who placed an ingot of magnesium in someone elses fire. They were seemingly under the influence of some hallucinates. Sure wonder how long they sat agape at the fire? It lit the surrounding hundred yards or so of redbuds back drop like ET was landing, for at least 30 minutes!

Posted by: Porkchop---------------------

Most of the weld advice that has been stated is spot on. when repairing a die cast part that has been in service the m.o. is always ,clean, weld, grind,
clean, weld, grind, until your results are acceptable. Caution, do not clean it with brake cleaner or carb cleaner, the left over residue when heated makes phosgene gas witch is a neurotoxin. this is no joke.
Consider using solvent then alumaklean (available at weld supply stores)
rinse with hot water, dry it & you're good to go.(always provide plenty of ventilation when using all the above processes)
Phosgene,( also known as nerve gas) was purposely used in ww1 dispenced in fog machines that made giant clouds that stay close to the ground. It wiped out entire regiments in minutes,(on all sides) so brutally nasty It was that the Geneva convention banned it as a weapon of war. So much for that.
Some friends were out camping & sombody brought a big piece of mag supercharger casting that had already gone boom off of a top fuel funny car, so in the big wood camp fire it went.............
It sat there for a while, then it started to melt& run all about the fire, then it started to burn& burn it did. Then.......it started to rain,& RAIN HEAVILY. Mag burns hot enough to decompose water into hydrogen& oxygen causing the whole mess to go pyro spectacular.
They were forced to rereat aproximatly1/4 mile away for about an hour,
during this time they observed a blue/white hemisphere of illumination
of the falling rain, the scale of which was a 200 yard radius. Let them tell you, this was reminicent of the 60's& happened in the mid 80's.
So much for this bit of bench racing, Best regards, Porkchop...

Hey Old M X Racer, Did those guys have any retinas left afterwards?
It sounds like they may have been driving while blind to begin with...

Posted by: Ol'89r---------------------

[QUOTE=Porkchop] Caution, do not clean it with brake cleaner or carb cleaner, the left over residue when heated makes phosgene gas witch is a neurotoxin.

Let me tell you, this was reminicent of the 60'sQUOTE]

Hey Porkchop.

Thanks for the heads-up on the phosgene gas. That may explain a few things.

Also, if you can remember the 60's, you wern't really there.

Posted by: Porkchop---------------------

Good morning OL'89R,
I started the 60's in diapers, & finished in the 4th grade on a honda mini trail 50. 1st outing was to Mel Hanna's place at the holiday/bean canyon area, taken out with the late drag boat racing champ Rapid Ray Caselli, my pop & friends. wow there's a flash back for ya. My pop was his crew& best friend. Mr. Ray was Kurt Caselli's great uncle,& an avid m.c. trail rider & racer, a great man & dear friend too.He gave me my first ride on the back of a BULTACO Matador 360, I was 7 at the time, from that point on... hook line& sinker

Best regards, Porkchop...

Posted by: Rich Rohrich---------------------

Porkchop - Great idea to bring up the dangers of mixing brake kleen with high heat. A well know bicycle frame builder out of North Carolina wrote about his really bad experiences from exposure to phosgene gas while TIG welding. It's worth a read for everyone even if they don't weld : http://www.brewracingframes.com/id75.htm

Posted by: jsantapau---------------------

damm that some scary stuff

I know I tested my luck in that respect. makes sense even though I never heard/paid attention of not using brake cleen while welding I know that using a flame to search for a refrigerant leak could kill you.

shouldn't of been to big of a mental jump to realize CFC's and heat aren't good.

Is acetone ok?

Posted by: Ol'89r---------------------

Quote:

Originally Posted by Porkchop

Good morning OL'89R,
1st outing was to Mel Hanna's place at the holiday/bean canyon area,
Best regards, Porkchop...

Wow! Small world.

I spent many weekends out at Mel's place. I remember some little red-headed kid named Bob running around on a mini-bike.

The kid was nuts.

He still is. Also remember the big wooden motorcycle in Mel's front yard.

Those were good times.

Posted by: Rich Rohrich---------------------

Quote:

Originally Posted by jsantapau

Is acetone ok?

Acetone has been my choice for years. As long as you handle it in a way that minimizes skin exposure and breathing the airborne vapors and you stay mindful of the basic fire hazzards that come with volatile solvents, it seems like one of the safest and most effective solvents for pre-welding clean up and basic engine clean up work.

Posted by: Porkchop---------------------

Thanks Mr. Rohrich, Several decades of designing, fabricating,& wrenching on movie props, specialty camera& F.X. equipment, tooling& bits& pieces for many types of vehicles, have taught me a few basic rules involving safety.
#1 What is forgotten or not known can kill.
#2 All rules apply all the time, aware of them or not.
#3 Mechanics, Welders, Machinists, Electricians, Pyrotechnicians all have this in common, there's good ones& there's dead ones.
#4 SAFETY MATTERS ALL OF THE TIME.
With Best Regards, Porkchop...

Posted by: IndyMX---------------------

I wonder if the newer "Chlorine Free" brake cleaners have this same problem??

Posted by: jsantapau---------------------

Thanks Rich,......Porkchop definately good rules to LIVE by...

Back the Tig welding of cases,

Now I have done quite a bit of industrial maintenance welding( stick and mig of steel and aluminum where the biggest problem was oxidation and paint, easy to get rid of witha grinder/sanblaster)
My question/story is I had a few old cases and cylinders and was using a tig basicly to learn and play. I tried boiling 1st with detergent and water and 2nd tap water to rinse and 3rd went and actually tried distilled water for a final rinse. When I would weld I would hit pockets of crap in the porousity of the castings. I went and lowered the amperage and raised the A/C on time and made "dry passes"to pull the impurities out, slowly increasing amperage and D/C time using a stainless brush in between passes to try and make a "skin" that i can weld to with decent penetration.
Although definately not pretty by any means of a good welder it appeared to have cured the ailment.
My questions are, Is this a reasonable way of curing the issue I had? Did I weaken the area of the castings when I made these dry passes to try and deep clean?

one thing I noticed for me was that I believed I was able to do a better job using an MGIndustries aluminum arc brazing rod with an oxy/acetylene torch ,mg420 rod if I remember right. well atleast it looked better

Posted by: Porkchop---------------------

Hello jsantapau, chop man here

we all know that aluminum sand castings very in quality from part to part. Some are real clean & dense with a thin boundry layer & a smooth surface.Others are rougher & have a thick boundry layer containing sand inclusions. Older cylinders were full of porosity so, when used oil permiates the casting.So there are 3 things that cause problems, surface oxidation & trapped oil / fuel varnish& paint.I would start by sand blasting or glass bead blasting, then dipping the part into an etching sollution like Alumaklene (diluted hydrochloric acid/ distilled water). Warm the part prior to dipping to 160 F.Dip time is 1 minute. Remove & rinse With hot water. Sand or grind The area to be welded to remove the casting skin. Repeat the etching - rinse process.
Next get ready to tig weld, use a mixture of helium & argon 3-6 cfm helium, 15 cfm argon. Preheat to 200-300 F. this is where you need a respirator & good ventilation. also do all the etching out side& be cautious of the fumes. Set the ac balance more favoring the cleaning mode.start the arc & run over the weld zone a couple of times at low amps, do this about 30-40- seconds then increase to 200-250amps & weld. If the repair requires machining, use 5356 rod,if not use 4043 rod . Make sure that the rod is clean & OXIDE FREE, SAND OR ETCH OLD ROD. Surface oxidation on aluminum burns at 6000 F.It does not melt since it is already chemically changed. Not dealing with it is the most common mistake that i hear people complain about. Confusing cleaning with deoxidizing is the second most common also. Use red tungsten preped with a blunt round end,3/32 or 1/8" & if you are using a big torch head increase shielding gas flow by 50%. Be sure you have good gas coverage.
The heat affected zone is completely annealed every where that you melted material. Cold working by hammer or shot peening will have a hardening affect on the weld zone, increasing it's strength. Solution heat treatment & artificial aging is the best way to get the most strength in an aluminum weldment & is only affective on certain alloys. These are the procedures implemented in mil-spec. fabricating shops. I hope that this info is helpfull to you. Best regards, Porkchop...

Posted by: whenfoxforks-ruled---------------------

Never welded aluminum myself, I know a guy at Service Honda. BUT, from a machining stand point, aluminum is a filthy metal, and like Pork Chops said, it varies A LOT from who ever has poured and cast it. Vintage Bob

Posted by: jsantapau---------------------

thanks porkchop, more food for thought when I am trying to kill a saturday afternoon.

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Case Welding

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