MGB: Frame rust on my '75

Hello...
I am back at replacing my rockers and floors on my '75 MGB....while cleaning off the old rust proofing I found this on the right frame rail...Is this car headed to the scrap yard?....I hope not...I would love to buy a better tub but finances will not allow it at this time...any suggestions on how I can fix this?...

thank you...

Get some heavy sheet, 14-16 gage, and make up a patch and weld it in. The area around it looks solid.

When you weld in the patch paint the sheet metal with weld thru primer first. Should be fine.

Don't worry. If you are going as far as changing floors and rockers, you are bound to find problems like that. Easy to fix with the floor pans out.

Anthony

thanks guys...should I just cut-out the section and butt weld in a new piece or weld a new piece over the top...since the floor is out I may be able to access from the inside as well...thanks again..

Clean it right back to check where it is thin.

Blasting is best.

Then cut out ratty bit.

Butt welding for strength is difficult and time consuming for something that is not seen..

Although purists would like it butted and ground smooth.

I would lap a piece about 5 mm bigger over the top over the edges tapped down a bit.

If any clearance was a issue , I would lap same piece from the inside.

If that job was presented to me, I would say a lap joint will cost $40.

A butt joint will cost $120.

The lap joint will be stronger.

Your choice.

In a similar situation I cut out the bad metal then made a patch that I drilled and puddle welded in place. After grinding the welds some, painting and undercoating, its hard to see where the patch is.

Back prime the patch and prime the area of the frame that you will be overlapping with a weld through primer.

I would butt weld.............that doesn't look like rust to me....looks like physical damage...no matter though...same fix.

Since the floor will be out, you should be able to get inside and fit a patch. To be honest, this might be a tricky piece to make due to the curvature of the rail. I would use a shrinker to get the shape.

I would also cut the repair piece (to be inserted inside the rail) much longer than the rusted area, then I would drill some holes in the rail and use then to plug weld the patch inside.

Pete