Shrinking and stretching technique

[Frosted]

Hi

I am trying to form the vents section on my defender and I'm not having much luck!
Anyone ever done it successfully?

I am struggling to understand how I can form this , see pic of the profile.
I can do the straight sections but the curved corners are very tricky.
I spent hours today trying to work out how to form the curve and keep The correct shape with no luck:-(

Thanks

 

[Wendelspanswick]

You would be best to use a full or partial hammer form, blocks of wood profiled to the required shape. Either a single block and use a hammer to work the material into the shape or a 2 part tool that you can either press or hammer together.
There is a thread I posted on making a radiator cowl for my Austin 7 special where I used a hammer form but the search facility is not bringing it up for some reason.

 

[Wendelspanswick]

Found it:
http://www.mig-welding.co.uk/forum/threads/new-radiator-surround-for-my-austin-big-7-special.42940/

 

[Frosted]

If you bash the sheet down into the shape and it folds it that a problem?
I read that when shrinking tucks you don't want it to fold.

Thanks

 

[Frosted]

Wow! Just had a look at your thread, amazing stuff.

I can have a go at making something out of wood and try it but I don't have a press only a club hammer.

I guess I could make the inverse of the mold and try it in the vice. It will take a while to make the molds:-)

 

[PSweeney]

not sure which bit you're trying to make but if it's a curved flange of any sort then get yourself a cheaper shrinker. I messed about with hammer forms and tuck shrinking etc and the shrinker is one of the best tools I own.

 

[hotrodder]

If you type hammerforming (or tuck shrinking) into youtube you find a bunch of vids that explain better but basically you just slowly work the metal down against the form concentrating on the high spots as the lows will take care of themselves i.e. as the metal puckers up keep bashing them down and the metal will gradually shrink and conform to the former. Don't forget to allow for the thickness of the sheet metal when making a former

 

[Frosted]

I gave up after a day of trying shrinking and stretching with a hammer, the radius of the curve was to tight I could not match it with out making the sheet tear.

I bought a full vent replacement which I can use on the inside as well BUT then I had a look at the end panel from the inside over to the hinge on the outside and I can't buy that piece. It is shrinking and stretching all over the place!

After looking at it for a few hours, I figure the best way to remake it is in 3 sections. I feel really crap as I have spent so much time, effort and money on doing the repairs to the bulkhead but that shrinking and stretching is to much to invest in. I can't get good results with tucks or hammer.

I'm done with it, life to short to ever do this agan. Spent the afternoon with my 5 yr old in the park learning to ride her bike :-)

I'm a broken man:-)

 

[Kent]

Drawing ain't your strong point is it

 

[Frosted]

No:-)

 

[optima21]

forward to 3m 20s and you well see that drawing is the issue (drawing as a process in metal forming)

 

[decca]

View attachment 70524 Hi

I am trying to form the vents section on my defender and I'm not having much luck!
Anyone ever done it successfully?

I am struggling to understand how I can form this , see pic of the profile.
I can do the straight sections but the curved corners are very tricky.
I spent hours today trying to work out how to form the curve and keep The correct shape with no luck:-(


View attachment 70523

Thanks

I am sure they do a repair panel for this and from memory they are not too expensive. I think YRM Metal Solutions.

 

[Frosted]

I ordered a full vent but sent it back it didn't fit very well.
I had another go and ended up slitting and welding to make the curve.

Just have to weld into place now.