...and speaking of forming ribs...

[Hofacker]

OK so far my attempts at rib forming have been way less than acceptable. One of the videos I saw, or perhaps it was at the Oshkosh forum, they used a lead slapper to smooth the flange down over the form block. Can someone direct me to one of these? or give me enough details to make one? Or other ideas, tricks and secrets?
Thanks,
CRH

[Sirota]

Is this what you're looking for?

http://search.eastwood.com/search?p=Q&ts=custom&w=slapped&pw=slapper&rt=spelling&isort=score

[Hofacker]

Is this what you're looking for?

http://search.eastwood.com/search?p=Q&ts=custom&w=slapped&pw=slapper&rt=spelling&isort=score

Sort of... The one I saw demonstrated was made of lead and may have been covered in leather. In any case the lead made it slightly flexible so it conformed to the curved surface of the rib and spread the force over a wider area and apparently reduced the stretching/expansion at the point of contact. If I remember the explanation correctly a hammer blow slightly compresses the aluminum at the point of contact causing it to expand/stretch in the plane perpendicular to the blow. I tried a simple piece of lead sheet. It did make the rib flange much smoother but it broke after only a few strokes of light slaps.

[vaflier]

I think what they use is a peice of lead stick such as plumbers use for cast iron pipe. It comes in sticks about 12 inches long and about 1/2 inch square. Go to your local plumbing supply house and see if they have it.

[crusty old aviator]

Use lead flashing, like they use on roofs (why isn't it spelled rooves? Stupid English: makes no sense!) It comes in different widths, but 6" should work. You can also use it for balancing flight control surfaces. Wear heavy nitrile gloves so you don't give yourself lead poisoning. You may be cracking the aluminium because the radius on the forming block is too small.

[Mike Switzer]

Sort of... The one I saw demonstrated was made of lead and may have been covered in leather Seems out of context on this forum but were they using a blackjack (also called a "slapper")?? If so they are sort of pricey on the ebay market as most police departments have outlawed their use. Bucheimer made the good ones. They would work really well for forming aluminum.

[martymayes]

OK so far my attempts at rib forming have been way less than acceptable. One of the videos I saw, or perhaps it was at the Oshkosh forum, they used a lead slapper to smooth the flange down over the form block. Can someone direct me to one of these? or give me enough details to make one? Or other ideas, tricks and secrets?

What have you been using up to this point?

[Byron J. Covey]

Is anyone still using John Thorpe's recommended method?


BJC

[FlyingRon]

Back when my son was racing soap box derby cars we used sheet lead to make the weights. They sell it to make shower pans with. Comes like 36" by whatever in a roll. Harder to find these days because people tend to use a rubber/plastic product now but it's still around.

[Hofacker]

What is John Thorpe's recommended method?
Thanks

[Byron J. Covey]

Thorp used a dolly bar to back up the flange material, and a plastic mallet wth a wedge shape to move the metal, about 1/4 th inch at a time, into the corner formed between the edge of the form block and the dolly. When the flange has been formed to a width of at least 5/8 th inch, most of the still-vertical material that remains is trimmed off with hand sheers, and the remaining material is slapped down with a solder bar.


BJC