Welding 1926 frame

We call em’ fishplates,but they are always a good idea,visually inspect the repaired area often and I think you are good to go,as someone mentioned I never trust a butt weld on thin guage material,welding is an art unto itself(like steam-a lot of science,a lot of craft)

hey. first I would say, that if the steel is cracked, you should fabricate a new member.

if you are not willing or able to make a new member, the cracks can be repaired. not with oxy acetylene tho, that s brazing, not welding.

Mig Tig or stick will all work, but I wouldn t recommend stick welding plug welds unless you are skilled.

to fix the cracks the procedure is as follows: drill holes at the end of each crack, also groove the crack deeply with a grinder. plug weld your holes by starting at the inside bottom edge and and SLOWLY weld around the outside edge of the hole and spiral your way to the center, similar to a pecan twirl. when you get to the center ,move back to the outside edge, without releasing your arc, and repeat the swirl until hole is filled to slightly above the base metal. the hole should be backed with ceramic before welding, but copper or brass will do in a pinch.

then weld the groove.

all of this should be done with the member clamped flat to a table of some kind, with spacers under it to allow for the backing ceramic or brass. allow to cool before unclamping and DO NOT grind the first side flat until the other side is cleaned of slag, grooved and welded as well.

if you grind the first side before you weld the second, you will probably get the steel too hot when you weld the second side,and crystallize it. then you will really see some cracks.

after the first side has cooled, flip it over and re clamp it flat, with spacers to allow for the weld material on the first side that still needs grinding flush. clean out the back side of the plug welds and repeat the pecan twirl weld on the second side. groove the crack from the second side and weld. then let it cool. do not grind flush until cool to reduce the risk of cracks.

I still think that the aftermarket member cracked for a reason. the steel was probably V-50 or A572 steel , which is harder than the frame steel, and more liable to crack.

make sure you use a 7018 rod or some type of 70 series structural weld material, if you use 6011 or any 60 series weld material you will be wasting your time.

you may be wasting your time anyway. making a new member would be more efficient and give you a greater chance for a successful repair


...not with oxy acetylene tho, that s brazing, not welding.

Not really:


Brazing differs from welding in that it does not involve melting the work pieces

Oxy-acetylene welding does melt the work pieces.

what you say is technically correct.

20 yrs in structural steel shop and I saw exactly zero oxy- acetylene welds, except for guys doing body work on their cars at lunchtime

Kevin, the 1926 Chevy line didn’t include a six cylinder engine. That didn’t happen until 1929. THAT engine was the grandfather of every inline six GM built all the way up to the 250 CID. In most cases it was possible to bolt a later tranny to an earlier I-6 engine and vice-versa. It’s been a good run.

Yes a good welder is the key, Had a friend of a friend stick weld a broken foot on my 1890 cast iron stove, general concensus, a no go, 25 years later still holding up. 71 nova he welded in a plate for a shock mount that rusted and punched through the body in the trunk, 21 years later traded that car in, stupid thing, wish I had it today.