Welding thin plate, with out distortion.

[The_Yellow_Ardvark]

This engine came my way the other day. I know it needs a lot of work. But being a "Transit" design. One designe between the flat base and the steped up base it is worth trying to save.

But theses bases are prone to cracking on the mounting points.


.

This one has a serries of cracks. To stiffen the base some one has bolted on Meccon angle plates. This was some thing Mamod approved off.


But in the past I have tried to fix the cracks.
By:
Mig.
Brazing.
Plus some tried tig on the plates.

No matter what I have tried the repairs stand out or do not work. New cracls form or the olds ones start up again.

One answer is get a new base, costly, had to find and removes the orginality from the engine.

Does any one know of a method that will work and not stand out?

 

[Morris]

Could you spot weld a reinforcing plate underneath? The holes could be re-drilled. Should all look as Mamod intended.

 

[The_Yellow_Ardvark]

We have found a solution.
A friend gave me a lot of old dead Mamod bases.
All cracked or distorted, we're extra plates have been fitted.

My friend who TIG welds sll day was up fir the challenge.

His best method was.
Strip all paint and rust off.
Drill a hole at the ends of each crack.
Dress the plates flat and reform and edges and corners.
Bolt or clamp the base in such away it can only expand in two directions.
Silver solder the cracks up. In small tacks or runs.
Then dress the welds as flat as the can before sanding back, with out overheating. He said that was hard.
Re drill the holes at the end of each crack, plug with solder.

Will I be doing this?
Only on rare bases.

The bases he fixed are now going to be sold by the friend who donated them.