Repairing Magnesium?

[Oregon_Native]

i know it can be welded but it is pretty dicey if not done correctly. it can also be brazed but that presents the same problem.

has any one used "JB Weld" with good results.

 

[chainsawworld]

what are you fixen' ? if you are just plugging a small hole in the fuel tank it will work well. are you trying to hold two pieces together either by butting or overlapping? i think we will need some more info. marty

 

[oldwild]

repaired the top and sides of the tank on my 1130 with JB weld, and yes the tank is magnesium. The one question that was asked of me by a guy at work is "Do I need to pressure test the tank?". There is no mechanical way to pressurize the tank during operation, there is only one line off the tank to the carb, no other lines or a duckbill installed.

 

[Oregon_Native]

just fixing a crack in the bottom of the fan shroud on my Pro Mac 610

nothing structural or water tight

 

[oldwild]

IMHO, I don't think you will have a problem. The JB weld is some pretty good stuff, first time I fixed a gas tank with it, but have used it on radiators in the past. I like the JB better since you can sand it down and get a decent look from it. Have tried Epoxy Putty, and does not look or work as good!

 

[Oregon_Native]

thanks for the opinions i think this weekend i will pull the cover and fix it.

 

[lesorubcheek]

I've used JB Weld with great results on one old Homelite 925 fuel tank. I won 3 parts saws at an auction for $30 on ebay a while back and decided to try to fix up 2 of them. One was in great shape but the other 2 tanks were corroded badly. I picked the best of the 2 and sandblasted the area first. The result was one hole about the size of a quarter and several small holes about the size of a BB running in a row for about 3 inches. I used a strand of fiberglass cloth for a backing and built up 3 or 4 layers of JB Weld sanding between each. Been together for about 6 months now and so far no signs of a leak at all. Not sure what the long term will be. For a small hole with no structural load you should have very good results. Just make sure to prep the area really well first. Clean it to remove all residue and roughen the surface with some course sandpaper before application (and clean again after sanding!). Good luck!
Dan

 

[Al Smith]

I have put the stuff,in a cylinder of a John Deere A,below the ring travel,and believe it or not,it works.It's actually better than bailing wire,duct tape,and tie wraps.

 

[ScooterDrew1983]

At school we are trying to fix a block (11hp 4-cycle). it had a split that was pushed out (by the rod). I will tell in a few days what the results were.

 

[Oregon_Native]

you know any farmer worth his salt can fix most things with bailing wire and ductape.

i fixed the oiler on my 610 with a piece of wide rubber electrical tape. it had a hole in the diaphram.

 

[Bills Oak]

610 Saw

Oregon--I've been looking for a diaphragm for you but no luck so far...I'll keep looking...BILL

 

[oldwild]

here is the pic of the tank on the 1130 before I JB welded it, will post pics of the finished tank when I get home from work.

 

[Crofter]

Very few shops will have the proper equipment to do a welding repair on Magnesium. You must have the proper filler alloy, not some non descript aluminum filler. The back side of the item must be shielded by argon / helium to prevent burning up. Corrosion has to be completely removed from both sides; even so porosity can be a problem and tanks often had to be sealed with epoxy (or seal all) to make them liquid tight after welding. Aside from the catching fire and special filler it welds very much like aluminum castings.

 

[David_T (MO)]

you know any farmer worth his salt can fix most things with bailing wire and ductape.

i fixed the oiler on my 610 with a piece of wide rubber electrical tape. it had a hole in the diaphram.

I fixed the damper on my wood stove with my daughter's elastic pony tail holder. (New mechanism was $300!!) Fix is still working good five years later.

 

[oldwild]

okay here are pictures of the tank, JB'd painted and coated!

 

[Al Smith]

Like Frank said,mag is a pain in the rear to weld.It must be perfectly clean,you must use argon,and the right filler.If you loose gas coverage,while heliarcing,it will catch on fire,and burn baby burn,nasty stuff.Mag.,like aluminum,is a sacrificing metal.By the process of electrolysis,the metal is etched away over the years,thus the leaky tanks,etc.I have not been able to figure a way to prevent this process from occurring.Perhaps a little zinc anode?Most of the time it's on a 40 year old saw,that has sat for years.Nice job on the gas tank.

 

[ScooterDrew1983]

thats good hiding. with that hiding you could fool an auto body tech. I have had classes in it & have seen very very few (auto body repairs) that look better.

 

[Lobo]

Boy, o' Boy, O'Boy, O'Boy, O'Boy that is one beauty of a job. I sure hope you are proud of your new tank.

 

[Oregon_Native]

i don't think my dad could have done better. he was a auto body tech for 30+ years.

 

[oldwild]

thanks guys! Lot of time and patience went into it! Could not find a new top, sooooo had to make do!