I've been making new front wings using stump shrinking instead of a shrinker machine. What is the best method for flattening the pleats on the outside face? If I whack it too much then if straightens out the curve. If I'm too soft then the depressions stay in place. Should I be using a small ball hammer from behind to push the depressions out before using the file? 1.5mm 5251 sheet.
I've had to make it in 3 foot lengths so I can weld the straight sections on later. My English Wheel is mounted on the bench and anything longer hits the wall.
In the trade, in days gone bye, (assuming the wings are Steel)we would SHRINK the pleats by using the oxy-acetylene torch, and heating the metal to red hot SPOTS, then dressing onto a dolly of similar profile to the wing. Final dressing can then be done with a "FLAPPER" sometimes called a "SPOON" These tools can be easily made by using an old file and shaping it to form the handle then sanding the teeth off to make the face smooth. If during final dressing LOW spots are found, these can either be lifted from the inside face with a "DIMPLING" hammer against a dolly then filed off. Alternatively the low spots can be lifted, by using a Flapper again, made with a file but this time (DON'T grind the teeth off) then by dressing the metal from the outside and shaped dolly on the inside, the teeth on the file will re-stretch the metal . The marks made by the teeth on the file can then be removed by filing.
In the case of Aluminium, the same procedure can be used but is made more difficult by the difference in the melting point of the material. Would recommend practice if using Aluminium.
I've made some slappers from old Morris springs polished up. The slapper spends more time re stretching the metal and little on pushing the low spots out. I'm using my anvil as a dolly and slapping from the inside surface to push the material of the low spots outwards. I'll try a small ball hammer again and see if I can lift the low spots outwards. It is only the second set I've made so am still learning how to 'move metal'.
Hi ,Looks like your doing well, Keep up the good work. Practice makes perfect and you'll get there in the end. I started my Apprenticeship in 1952 and still learning.
26-11-2017, 01:24 PM (This post was last modified: 26-11-2017, 01:26 PM by Duncan Grimmond.)
I find that a pair of mole-grips with tongue-groove additions are very useful for crimping the edges into pleats. Together with a rawhide or wooden mallet against a dolly you can shrink these quite successfully. Much easier in aluminium of course...
BTW, the special is coming along nicely, crack on!
26-11-2017, 02:24 PM (This post was last modified: 26-11-2017, 02:26 PM by cardiffrob.)
Ooooo...nice idea. I might try to make some of those. Easier than using the tree stump. Thanks, Duncan.
This 5251 is a lot more rigid than the 1050 grade commercial ali I used on the inner wheel tubs etc. and it is much more resistant to being moved abaout, even after re-annealing.
5251 too intractable for my taste and it makes hard work out of what I regard as a pleasure.
The toggle action of the mole-grips applies a lot more force than my arthritic fingers can manage!
I couldn't find a local supply of 3000 series ali so it was 5251 or 1050 and the pure ali 1050 sheet is so soft that it loses shape as soon as you tighten down a bolt on it.
For the benefit of anyone else trying to do this, most commercial grades of ali that are soft/weak are 1050 pure ali which doesn't corrode too easily but is not strong. 3003 is better and can hold shape quite well but is hard to find. 5251 is used for making structural things like boxes, water containers etc and is much harder to form, even after regular annealing. The benefit is that it holds shape very well. My contoured dashboard is 1050 and my door skins are 5251.
Those pliers look like a better bet than what I've been using. Always handy to see how other people do these jobs (Isn't Youtube great!!!) and what tools they utilise. I've got a couple of polished Crown Green Bowling balls, a tow hitch and a Cobbler's Last as some of my forming tools.
