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Cast Aluminum Repair

brendonv

Tree Hugger
Joined
Mar 6, 2005
Messages
7,156
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Oxford, Connecticut
I just acquired a 40 year old 2 stroke Benelli mini bike from my grandfather yesterday.

There are 2 parts on the side case that need to be repaired. One is a little tab that had broken off, and there is a small chunk taken out of the bottem of the case.

Anyone have any ideas how or what these area's can be repaired with thats gonna last, and look decent?

Al?

Thanks,

Brendon
 
C

Chisel Tooth

Guest
Yep Steve is right you need to find someone that can tig weld it for you. Check the phone book or ask around.
See Ya
Mike
 
R

RaisedByWolves

Guest
I hate to put a damper on things, but its nearly impossable to get good results welding cast aluminum.


Cast alu is porus and has some inclusions, if the pores arent filled with dirt/oil (you cant see it or clean it out) then the junk in the metal will put the kybosh on the deal.


Some of the older stuff was made better, but make sure their not going to charge you if it dosent work out.


.
 

JIML

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Oct 17, 2005
Messages
480
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Indiana
Wish you lived closer, Id fix ya right up. I can weld pretty much anything.
 
R

Rotax Robert

Guest
Yes, it can be tigged up. It is quite a bit tougher due to the porous conditions ie: dirt oil etc. Any compitent welder can do this for you.
I just watched it done the other day with good results.
 
R

RaisedByWolves

Guest
Yes, it can be tigged up. It is quite a bit tougher due to the porous conditions ie: dirt oil etc. Any compitent welder can do this for you.
I just watched it done the other day with good results.


I stand corrected!


Apparently I know no competent welders.......:D




I have personally used the alumiloy and found it tiring and difficult but entirely useble once you get the hang of it.


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R

Rotax Robert

Guest
Talked to my buddy who does this and says he uses 4041 aluminium which is soft. If you use hard rod you will be chasing cracks forever. Hope this helps
 

Dave Shepard

Square peg, round world.
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Oct 28, 2007
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Alford, MA
I have not heard of 4041. There are only two alloys available around here, the 4043, and 5356, which is supposed to be more difficult to weld with. I have welded a bunch of the cast, agree that the porosity will be a problem. With a little patience, it shoule be repairable. Now forged on the other hand is like welding butter, smoooooth! I would avoid the MIG process for this type of aluminum welding, it requires a high travel speed and deposition rate, and will not tolerate the porosity at all. It is much better suited to building truck bodies of new material, or some such production application.


Dave
 

Al Smith

Mac Daddy
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Northern Ohio
I can TIG like a champ on stainless.Aluminum however is my Waterloo.It does make a decent beer can though.:D

I have a buddy that has a welding shop,damn good aluminum welder,pizz poor electrican.It works out well.
 
R

Rotax Robert

Guest
may have gotten the rod # wrong, however I have watched many caseings, bellhousings, etc being done. I am not the expert on this, but yes it can be done and quite successfully.
 

JIML

Treehouser
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Oct 17, 2005
Messages
480
Location
Indiana
4043 is what I use alot of times on cast, flows out nicer and doesn't crack near as bad..
 

Stumper

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Colorado
A local Welder repaired my chipper engine governor after it snapped off at the mounting flanges a few years ago. He was recommended by other welders. He knows his stuff and it just keeps on working. Not only did he stitch it back together he used some bits of scrap to reinforce the places that fatigued and failed after 20 years of use. I'm told that that guy is also capable of welding magnesium.( For those that don't know magnesium = firestarter)
 

sotc

Dormant hero!!
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So. Oregon
wow justin, that doesnt seem like a good idea! i know its safer in block form but still!
 

Al Smith

Mac Daddy
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Northern Ohio
A . I'm told that that guy is also capable of welding magnesium.( For those that don't know magnesium = firestarter)
My buddy with the shop is an ace at mag.He welded the beat up case on my 2100 Homie.He said mag is nearly impossible to get clean enough.We ground the dickens out of it and used some type of acid to clean the metal,prior to.

Actually I've had a goodly amount of cast alumunum welded over the years and it's all worked out.Any metal has a certain degree of weldability if you know how.I'm a steel and cast iron man myself.
 
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olyman

Guest
have tigged mag before--on a stud mount on a homey---teacher said i couldnt weld in a hole--at first---i saw why--but after i welded the hole shut--he asked how in hell i did that--him being a sarcastic person--i said none of your business--he laughed--i told him how at the end of the class period--he said--stick around this class for a while----i did--still good friends to this day---and not many made friends with him-------
 

Dave Shepard

Square peg, round world.
Joined
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Messages
4,407
Location
Alford, MA
Yeah olyman, fess up!;)

I have never welded mag either, but have seen and heard of some bad mag stories. If you welded it in an argon purge like titanium, I would think you would be alright. I now the shavings are the most dangerous, like sotc said.


Dave
 
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