Scavenger Hunt: building a ‘slide hammer’, island style
Terrible picture, but this is my 'slide hammer'. Imagine that I will place the upper end inside the shaft tube then put the washer and nut on that end and then hit the bottom plate from outside with a sledge hammer to extract just the old bronze tube. Yeah, I know…it's really boring when it isn't your problem…anyway, I was going to use that rusty hunk of metal as the 'slide' part of the 'slide hammer'…but it turns out it works better if I just whack the hell out of it with the sledge hammer.
I found Cesar leaned up against a shaded post near a fishing boat he was about to paint, talking with Benois, the metal worker.
“Belleza pura,” I said, offering the Brazilian greeting he’d taught me. “Hey, do you know where I can find a 6’ steel rod or pipe threaded at both ends?”
“Well…the plumbing store sells 18ft pieces of ¾” steel pipe threaded on both ends.”
“Oh and Ben, could you make me a steel washer of exactly these dimensions?” I said, pointing to my diagram.
“What is that?” They both said at once.
“It’s a ‘slide hammer’. I’m going to use it to extract my shaft log. Or in French, you could call it an ‘extracteuuuuuuuuuuur’.” I explained.
They nodded and went back to their discussion. It took a few days to gather all the pieces, but by Thursday morning Jacques had cut down my 18’ pipe to 6’ and welded a plate onto the end (which would be where I would ‘hammer’). Ben had made me the washer, but out of aluminum rather than steel. Before I complained, I figured I’d give it a shot.
I set it all up and borrowed a massive sledge hammer from the yard, and went for it. I swung the hulking head of the hammer and shocked myself by how hard it slammed into the welded plate. By the 30th hit, though, I’d broken through the welding on the plate and the tube hadn’t budged. I went up to see what was happening inside and found the aluminum washer was completely bent.
And so, I gave up…my island style ‘extracteur’ had failed. Back to the drawing board…
3 Comments
Sal
February 25, 2010Far from boring. While I, and countless others, sit at our computer screens in southern California and fantasize of global travel, it’s good to be reminded that the “romance” includes slide hammers in dry dock. You’re not missing too much back here.
Bill Humphreys
February 25, 2010Hi Liz.
Read your frustration with your slide hammer. In a pinch I have used a strong rope or cable to the welded end of your unit and the head of the sledge. Use something that has little stretch.. Then swing at the air letting the hammer do the work with the cable transferring the shock load in line with the pipe. Hitting the welded piece on one side will break the weld due to the uneven loading. One aluminum washer is not good, but a few will work also if steel is too hard to fashion. I think your guy is using hole saws, first a big one then a small one using the same pilot drill hole. Also the bronze tube is glued in, and heat is the enemy of plastic and fiberglass, it will weaken the bond, but will also change the temper of the bronze, so heat the end not being driven or it will mushroom. I assume you will use the same tube after filling the voids with epoxy and hopefully collodial silica filler or microfibers. Maybe filling the area through holes drilled perpendicular to the tube to get to the voids would work as well? I saw some exploratory holes in your pictures that may have found voids. A few extra holes are filled easily and help insure to find all the voids. I search for hidden voids with a small hammer of hard plastic, tapping the area and listening for solid or not so solid sounds. A hole at the bottom and another at the top of the void help when you fill from the bottom until the stuff comes out the top in a mayonnaise type consistency of epoxy & filler. You will need a large syringe to squirt the stuff into the hole, or keep pushing it in with a putty knife. Bonne chance. Watch for filler appearing inside the bronze tube through the odd hole, it is much easier to deal with when partially cured however you reassemble the structure. BTW flood the void areas with acetone before epoxying for a good glue bond to the existing structure. Sand the bronze shiny for a good bond to that. Dried salt is a debonder too. Let the acetone evaporate too before reglueing. You will succeed now that you know what you are dealing with. Hope you get this
Kirk McGeorge
February 25, 2010Hiya Liz,
Sorry we missed you in French Polynesia. Our wakes must have met somewhere between Moorea and Huahine. We left Bora Bora and are now in Pago Pago.
Not sure the details of your shaft log woes… but I rebuilt mine a while back by inserting a length of carbon fiber WINDSURFER MAST up the inside and marked & cut it to the correct kength. Then I removed it and slathered thickened epoxy on the outside of it and then pushed it back up inside the dammaged log and the job was done! The mast section is super strong and thin walled enough so that the prop shaft could continue spinning inside without touching the new sleeve.
Just another angle on an easy fix for your shaft log.
We’ll be in Pago Pago until the end of Cyclone Season and head for Vavau, Tonga around April or May. Hope to see you out here sometime. All the Best – All the Time,
Kirk, Cath & Stuart ~~~_/) ~~~ the Gallivanters