Could I ask advice please on the correct way to repair a steel vehicle
chassis. I understand the proper way for say a rectangle type repair
is to have the top part of the replacement plate sharter than the
bottom....sort of like this /---\

/-----\
sort of shape...is this correct please. I understand it makes a
stronger joint,
also if the correct way is to make a flush joint do you just wedge the
new piece in place or is there a better way before you start to make
the take welds.
Thanks very much

Smokeyone

SHORTER AND TACK WELDS DO YOU
MEAN ?????????????

The purpose of an angled cut on your repair patch is to prevent a stress
riser. If cut square across the patch area would be very stiff but right at
the edge of the patch it would be the point of flexure. This would create a
point of cracking in the future as the frame is put into service. By having
an angle cut the point of change from rigid to flexible is spread out and
less likely to create a start for cracks.
I am not sure what you mean by wedging the new piece in but a close fit
is ideal. You don't have to weld all around. Short one inch stitches with
an inch between will allow the patch to flex a bit.
Are you repairing a cracked area or an area that is corroded?
Randy


"Smokeyone" wrote in message
om...
Could I ask advice please on the correct way to repair a steel vehicle
chassis. I understand the proper way for say a rectangle type repair
is to have the top part of the replacement plate sharter than the
bottom....sort of like this /---\

/-----\
sort of shape...is this correct please. I understand it makes a
stronger joint,
also if the correct way is to make a flush joint do you just wedge the
new piece in place or is there a better way before you start to make
the take welds.
Thanks very much

Smokeyone

"R. Zimmerman" wrote in message news:wJGnb.210329$6C4.80218@pd7tw1no...
The purpose of an angled cut on your repair patch is to prevent a stress
riser. If cut square across the patch area would be very stiff but right at
the edge of the patch it would be the point of flexure. This would create a
point of cracking in the future as the frame is put into service. By having
an angle cut the point of change from rigid to flexible is spread out and
less likely to create a start for cracks.
I am not sure what you mean by wedging the new piece in but a close fit
is ideal. You don't have to weld all around. Short one inch stitches with
an inch between will allow the patch to flex a bit.
Are you repairing a cracked area or an area that is corroded?
Randy


"Smokeyone" wrote in message
om...
Could I ask advice please on the correct way to repair a steel vehicle
chassis. I understand the proper way for say a rectangle type repair
is to have the top part of the replacement plate sharter than the
bottom....sort of like this /---\

/-----\
sort of shape...is this correct please. I understand it makes a
stronger joint,
also if the correct way is to make a flush joint do you just wedge the
new piece in place or is there a better way before you start to make
the take welds.
Thanks very much

Smokeyone


Hello

Thanks for the info. The repairs are to rusted areas that have been
completely cut out. The welds do not have to be ground flush but I
assume if the new steel was flush with the old it be both neater and
stronger. How do you hold the new metal in place, also stopping it
from falling inside the chassis - while you weld it.

Thanks again

Smokeyone

Thanks for the info. The repairs are to rusted areas that have been
completely cut out. The welds do not have to be ground flush but I
assume if the new steel was flush with the old it be both neater and
stronger. How do you hold the new metal in place, also stopping it
from falling inside the chassis - while you weld it.

Thanks again

Smokeyone

There are a variety of clamps & tools for this but the cheapest way is to
tack weld a piece of scrap metal onto the piece to hold it with then tack
weld it in place. It helps to have an auto welding mask or a helper at this
point. Since you are working on a chassis, the finished job doesn't have to
be beautiful, that makes the job easier.
Try a search for car (auto) restoration for a whole load of info on this
subject.
When you say the rust has been cut out, I bet it hasn't. You will almost
certainly find the original metal is very thin when you begin to weld to it.
Good luck.

John

"John Manders" wrote in message ...
Thanks for the info. The repairs are to rusted areas that have been
completely cut out. The welds do not have to be ground flush but I
assume if the new steel was flush with the old it be both neater and
stronger. How do you hold the new metal in place, also stopping it
from falling inside the chassis - while you weld it.

Thanks again

Smokeyone

There are a variety of clamps & tools for this but the cheapest way is to
tack weld a piece of scrap metal onto the piece to hold it with then tack
weld it in place. It helps to have an auto welding mask or a helper at this
point. Since you are working on a chassis, the finished job doesn't have to
be beautiful, that makes the job easier.
Try a search for car (auto) restoration for a whole load of info on this
subject.
When you say the rust has been cut out, I bet it hasn't. You will almost
certainly find the original metal is very thin when you begin to weld to it.
Good luck.

John

Thanks for the suggestions

Smokeyone