Forney aluminum wire repair

[whtbaron]

I have an older (mid 70's) Forney 225 amp AC buzz box that has served us well for many years. I realize these were entry level machines for their time, but we have had very few issues with it. Other than the on/off switch, the only problem area is the female electrode plugins and aluminum wiring. The plugins are held in place with plastic insulators which eventually strip out with use. Unfortunately the 90 amp plugin that gets used the most was also used to connect 2 large wires inside. When it comes loose the wires also get shook loose and over the years I have shortened them to the limit. The solution seems fairly obvious... connect the two wires inside and run a new wire to the plugin. My question is what the proper connections and wire would be to used to avoid future issues with the aluminum wiring. One is fairly large ( I'm guessing around 1/4" in dia.) so to take the load of the 2 wires, it will need to be fairly heavy, and the connector that joins all 3 will have to be big enough to accommodate them all.

[shovelon]

Any way to use copper?

[whtbaron]

Anything I've ever heard about mixing and matching aluminum to copper in household wiring generally had an unhappy ending. For the most part this machine has been pretty trouble free for the last 40 years, so I'm inclined to let the sleeping beast lay despite the bad rep that aluminum wiring has. The plugins are brass, so I'm tempted to say a brass connection would probably work if I could find some heavy aluminum wire to add in, but I was hoping to hear from people that have actually tried it and had some experience. Interestingly enough if you look at the Forney web site, there are very few parts listed for the old machines, but I know I can still access the plugins through my regular parts guys.

[rhunt]

Any pictures of what it is that you are describing? Have you tried Grainger? Best Bob

[Dantheharleyman99]

When I was a teen I worked doing commercial HVAC. and it was mandatory to use a brass sleeve or terminal to connect aluminum wire to any type of terminal. For the life of me I can't remember why, but it had something to do with oxidation issues from the hi current compressors (like a high current coil in a welder) might be worth looking into.

[whtbaron]

The issues of mixing the two dissimilar metals are related to different expansion rates and potential electrolysis resulting in oxidation at the joint. When the copper and aluminum get warm and expand, the aluminum does it at a faster rate. When this happens repeatedly over time, it loosens the connection and causes arcing. Arcs at the electrode are a good thing...inside the welder not so much. Any oxidation at the joint makes the connection issues even worse. Got another wet day buy I've been busy getting the combine ready for harvest. I don't know of any Grainger outlets locally, but it might be worth another search online. As soon as I get a chance I'll open it up again and get some pics.

[whtbaron]

As long as I join it to another larger piece of Aluminum wire ( if I can get it... I have no idea how hard it is to get large sizes of aluminum wire these days, it really seems to have fallen out of favor), the obvious choice would be to either use an aluminum connector, or avoid it altogether. Since this is a welding site, I've also toyed with the idea of getting all 3 wires welded together. Not the best for servicing, but like I said, this machine hasn't required a lot of servicing in the last 40 yrs so if it ever does develop serious internal issues, it would likely get tossed in favor of a new AC/DC machine. Until I got searching for parts, I had no idea that Forney was still making new ones.

[shovelon]

Union Carbide Linde division went with alum buss wires in the 80s. They were quarter inch aluminum rods with copper crimped lugs at the ends. Between the copper and alum was stainless steel mesh. They always worked loose and arced at those joints.

In my case I had a Heliarc 300 with alum wires. The joints would loosen, arc, heat, and wreck the contact springs in the current selectors. Many an alum buss wire did I replace with copper to copper replacements that I fabbed up and silver brazed the joints. The machine was rock solid except for those stupid wires.

[Fireman Bill]

Copper has a chemical reaction when mated with aluminum and forms a coating between the two. A corrosion paste is used when this typ of connection needs to be used.
Just saying..................

[whtbaron]

Finally got a rainy day to take some pics, but I still haven't tried to source the aluminum wire. Included a pic of the electrode plugins (output jacks) with part #'s since I didn't see those on the Forney site, but they are readily available. You'll notice the top one was recently changed. The problem isn't the plugin per se but the plastic insulator on the front that doubles as a retaining nut... it really needed to be cast with a threaded brass insert for better tightening. The problem is on the second connector down (80 -100 amp is popular) that is also used to connect 2 wires. Any movement and the connection shakes loose, resulting in the need to shorten the wires until I have finally run out of extra length.

[rhunt]

Here is something that may help you, look up aluminum/copper bug, they come in many different sizes. These wire connectors are used to join copper to aluminum and aluminum to aluminum. They also make solid copper bugs to connect copper to copper. If using the aluminum to copper bug, this bug has an separator plate that keeps the aluminum from touching the copper thus eliminating the corrosive effects of the dissimilar metals. This bug would enable you to extend your lead to reach your new connector/jack as you have pictured above, by using copper wire. However, for a faster quick fix to get this equipment working again, you could exchange one of the good jacks with the bad one and move on. Use Noalox as a joint compound when using the bug on aluminum and tape this connection when finished. Just my thoughts, Bob

[DSW]

Bob I think his issue is that the wires in the past have shorted and been trimmed to repair the issue. Now the wires are just too short to use any longer, hence the need for a splice and alum wire.


As Bob suggested use Noalox on the fittings. It's used to help prevent dissimilar corrosion between alum and copper/brass. Alum wire is still used for service entrance connections in homes. Copper is just way too expensive in long lengths of heavy wire. Most that I have seen though is stranded, not solid. I used to have some solid alum wire but I think I scrapped it after stripping the insulation. I have no idea where it came from at this point.

I bet a good electrical supply would point you in the right direction. They may or may not have heavy gauge solid alum wire. If not they may have something as a substitute for the short length you need. I know they'll have the connectors. Some I've seen for alum to alum connections are simply slip on sleeves they crush with a crimper. Others like mentioned are done with set screws.

[rhunt]

Doug, the reason I mentioned the bug was for the benefit of adding a piece of copper wire to the already shortened aluminum wires. Bob

[Willie B]

Aluminum wire in large sizes is likely to be stranded. I'd use a tin plated split bolt wire connector with spacer bar to couple the three conductors, then stranded copper to the welder lead terminal. Clean all metal shiny with fine sandpaper or stainless wire brush, then coat everything with Noalox from Ideal. Never let copper touch aluminum.

[Sandy]

Power Co guys use solid aluminum wires for tying the stranded conductors to the insulators and what have ya. A lot of it from #8 to #4 laying around where they have done rehab work. Or go hit them up for a few chunks.

[whtbaron]

I've talked to a local electrician and he says he's got short pieces of aluminum that should work... now it's just a case of finding the right connector, preferably aluminum as well. Shouldn't be a big deal but he might have to order it in. I also know some guys at a local Hutterite colony that spend their days welding stainless steel and aluminum. If getting a good connector becomes problematic I'll just get all 3 wires welded together. The bug and Naolox mentioned above looks like an option as well. The wires are fairly large in diameter. The smallest incoming is 5/32 ( 8 or 9 guage), the larger is 7/32 (4 or 5 guage) and the biggest I can go into the terminal is 5/16 (1 to 2/0 guage). At this point the welder is still working fine and I made sure everything was tight when I opened it up to take the picture, but I do know that the next time those wires burn off they will be too short to reconnect.

[Willie B]

I know I'm sounding repetitive, These welders were throw away welders when they were built. There are thousands of choices of better welders to be had for a small investment. Look around Craigslist. Buy a nice old welder that was well built when new.
Or, do what I do pretty often, grab a Burndy KSU23 Split bolt, coat it and the conductors with Noalox, use the spacer bar to separate aluminum from copper. I don't see the evil in stranded copper. As the old builder would say, "there's no need of turnin' this into a project!"

[whtbaron]

If you look around the other posts on Forney's, you'll hear the same thing over and over. They had a bad rep for the aluminum wire and being cheap, but they last forever and they weld so damn nice and smooth! I'm pretty sure I can have this fixed for less than $30 so I don't think I'll toss it in the trash just yet. I've got other welders around, but this will do as good of a job as the others. It's only real shortcoming is being AC only, so if it gets replaced it will be with a new AC/DC machine.... which will obviously cost me a lot more than $30. I'm out in the sticks so those deals on Craig's list become cost prohibitive when you factor in freight. Watching the local auctions etc., I'd be further ahead to buy new.

[hatzie]

The FNG might actually have something useful to contribute here.

Not all Forney welders are cheapo units. Undesirable to most? Yes. All of them cheaply built? No.
I picked up a 1940's or 1950's Forney C-4 farm welder around 20 years ago. She was old and abused but after cleanup, some body work, and replacing 3 stinger socket isolators she welded so nice and smooth I've never looked at anything else for stick.
I replaced the non-conductive isolation nuts and fiber washers. The sockets are brass on my C-4 and the transformer wire is copper. The plastic nuts don't quite match the old material but it works...
She weighs quite a bit more than some of the new cheap Lincoln buzz boxes I've moved for friends. The C4 probably has a bit more in the way of copper and iron than the '70s and '80s through now models the transformer wire is obviously copper.

Aluminum house wiring can be made safe using special hydraulic crimped ferrules. I would think you could find an electrician that could properly crimp CU to AL just like they do with AL Romex in AL wired houses.
http://www.klauke.com/en/electrical/...and-aluminium/
http://inspectapedia.com/aluminum/Al...ir_Methods.htm

[whtbaron]

Those plastic nuts are the real weak link on these machines... they eventually strip but aren't that expensive to replace. If you noticed the burnt paint in one of my pics, you'll note that one actually shorted once. If they had cast those nuts with a threaded brass sleeve they would last much longer. Maybe there's a job opportunity for someone that moulds plastic.

[hatzie]

The new plastic nuts are softer than the fairly brittle originals. I haven't busted any of the originals that were still OK on my machine but it came to me with missing or damaged plastic nuts.
The prior owners stored it under a wood pile and threw firewood at it... I brought it home from the Springfield swap meet, did some hammer and dolly work on the aluminum case, and re-assembled it with some replacement isolation nuts. She's a trooper. She makes some beautiful welds with ease including my first project with her... an angle iron 4 wheel dolly I made to replace the missing wheels and feet.

[whtbaron]

They are heavy... if you look at the pics you'll see I've added a handle at the back for moving it, and not visible is the lawnmower style wheels on the back that I added for dragging it around. Since this seems to be "the" Forney thread, put a pic of yours up here too. Be cool if u had a "before" pic with the woodpile damage.

[Willie B]

How much you gonna spend to save a welder that sold new for $200.00

[whtbaron]

I don't anticipate this costing much over $30...if that. Seems like cheap maintenance for something that's been pretty much trouble free for over 30 yrs. Knowing what I do about the machine I would consider a complete rebuild and putting another $200 into it because chances are good that it will still outlast lots of $200 machines being sold today. My first SnapOn ratchet only cost me $14... but I'm not ready to throw it away yet either.

[hatzie]

The dollar was a heluva lot more valuable in 1970. Mom bought a 1970 Oldsmobile Delta 88 for $4,000 in late 1970. A car of that class will set you back $40,000 or more now. Using that as a benchmark that $200 welder cost $2,000 2014 dollars. It also means that new $200 Lincoln is a POS because there's no way they saved $1,800 by using Chinese slave labor.
I'd call you dollars ahead if it only costs $30 to make it a complete machine instead of spending 10x that to buy a POS that might make it a few decades. Your grandson will still be using it if we can afford to use enough electricity to weld things in the future.

If you have a lathe you could spin up an insulator out of plastic that would have a shoulder that protrudes through the front. You might have to drill the front out a bit larger. The other option is to put a hook on the cart and hang a loop in the stinger and ground wires from it to take the strain off the sockets. I did this and I also unplug them when she isn't in use.