Friday, April 23, 2010

Hose suspenders - Part 1

OK, I'll openly admit it, I'm not a tradesman... I'm a dabbler. If you haven't already noticed it, some of what I show in these pages are mistakes, errors, and substandard welding. It's not from a lack of wanting, just a lack of training. Half of what I put these pages up is to show what can be done, the other half is to show what shouldn't...
I was once told that a Wise man learns from the mistakes of others - learn from mine. (you won't have time to do them all yourself!!!)

I offered to make some "hose suspenders". These are used by firemen for securing hoses running up ladders during structural fires. The suspender comprises two main parts, the first being made of steel, and resembling a large fish-hook. A sketch of it is shown on the welding table below....
The one I saw (to take dimensions from) had been forged from 3/8' (10mm) rod, but since I haven't built my forge yet, I figured I'd built these from welded pieces of steel. The ring at the bottom would be made from small pieces of pipe, and the two "hooks" would be made from 3/8" rod.

I obtained some 3/8" rod from the workshop, but all that was available was square rod, not round. I decided to make the "round hook" first by bending the rod around one of the pipe offcuts left over from Bender's legs. I welded the offcut to a scrap of steel as a jig.

The above photo shows the steel in the jig (Mk1) - all chalked up for the photo, and the arrow pointing the direction of the bend.

Cold bending 3/8" square rod was fairly easy, but getting it to conform to that curve was not easy. Sure I could have threatened it with the hammer, or swore at it, but I needed a better plan.

Mk2 jig basically added a "slipper" to the bend - a 1/2" (13mm) rod was welded in the centre of the pipe via a hole and plug weld, and a pipe handle was made to hold a slipper against the rod being bent. The slipper was nothing special, just a 1" (25mm) piece of pipe dropped over a 1/2" (13mm) rod.

The slipper keeps the 3/8" rod against the former in the jig through the entire rotation of the slipper pipe. This forces the rod to bend just as tightly all the way around the 180 degree turn.
The photo below shows the Mk2 jig, with the pipe (and slipper) at the commencement of a bend

about 20 degrees through the bend, I would place the larger yellow pipe on the slipper pipe as a handle to increase leverage, and then complete the bend

I found it easier to place my body between the end of the rod, and the pipe handle, using my hip to guide the rod stock, and my hands to guide the pipe. Sounds awkward, but it was actually easy, and quite quick. Once the rod was bent, I aligned it with a mark on the jig, and cut it off with the grinder, and started again. All up, nine hooks were made in about two hours including making, and remaking the jigs.
Part 2 will cover why the same solution failed for the other hooks.

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