If the hinges had through holes, one long peice of straight silversteel would keep them aligned reasonably well, and then weld a cap afterwards?
Sounds sensible, but they don't. The lower part of each hinge has the pin integrated into it. I'd wondered about making something (a long bar with some offset pieces bolted to it to support the hinge pieces while welding them) but it felt like too much hassle in the end and I'm not convinced it would have helped anyway. After tack-welding them in place, the hinges moved freely and could be separated easily. I think they must have moved a bit more when the final weld was done and I'm not convinced a fixture would prevent that movement. Having said that, I'm not exactly an expert welder, so it's highly likely I don't know what I'm talking about!
Take some coarse emery to each pin and take the diameter down a gnat's?
Or get the gas on it and encourage whatever hinge over a bit?
I'd imagine there's a method that is used by most professionals when they fit these hinges. I'd be interested to hear from anyone who has done so.
Looking good! I think its going to mighty fiddly working that element around the bends!On inspecting the steel sheets (in their citric acid bath) this morning, they still looked slightly rusty, but I pulled them out and gave them a quick wipe with a tissue and the rust came off really easily. At this point, you have to work fast as it's astonishing how quickly they'll start to tarnish once they're out of the acid bath.
I wiped them over with some paper towel and then attacked them with a wire brush. I could have oiled them but I knew I was going to weld them almost immediately so I would have had to clean the oil off again very soon. The wire brush was quite a good work-out for the start of the day anyway considering how much the temperature had dropped overnight.
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The insert for the back of the control cabinet needed a couple of little cut-outs (because of the weld nuts that I fitted yesterday). I cut out the pockets with a junior hacksaw (as it has finer teeth than my big hacksaw and hence is better for cutting thin sheet). I probably wrecked the blade in the process as it took my an embarrassing amount of time to remember that it was set up (as they usually are) to cut on the push stroke and I've been doing a lot of work with Japanese woodwork pull saws recently! Nevertheless, it did the job quite quickly:
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I could then place the sheet into the back panel and do a few tack welds all the way round. I'd been doing quite well at welding yesterday but, while it went fine on these joints, I dipped the tungsten in the weld pool quite a few times today, making me glad I had quite a lot of them ready ground so I could quickly swap them out after each mistake. Anyway, it got done:
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As did the door insert, which had a somewhat higher density of tacks along the left-hand edge as that's where all the controls are and hence it'll see a bit more force from push buttons being pressed:
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Overnight, I'd 3D-printed a guide (with a 17 mm wide slot) to help with preparing the blocks for the heating element:
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The plan with this is to have the heating element captive (by having an undercut slot). I'm not especially confident of how that will work as the fire bricks are incredibly brittle and it wouldn't take much for the retaining lip to break.
To hold the guide in place, I expected (correctly as it turned out) to need to use clamps and such-like. The little cross-pieces you can see fitted to the guide are there to hold the fingers in place while routing grooves in other areas (but they obviously need to be removed when the router is in that area). In a fit of optimism, I decided to try some double-sided tape just on the off-chance it would stick to the fire bricks:
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After removing the backing paper, I placed the frame on the bricks and covered it in heavy bits of steel to hold it in place.
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Once it had been left for 10 minutes or so, I removed the weights. It took the lightest of touches to remove the guide from the bricks, so the tape didn't work. Not a great surprise, but it was worth a try. These are the router bits and guide bushes I intended to use:
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In the end I didn't bother with the little key-hole cutter (which was only intended to be used for a light undercut to deal with the area where the cove (?) bit didn't cut). The 6.35 mm (1/4") straight bit was used with a 14 mm guide bush, which hence allowed it to move 3 mm in the 17 mm wide slot, producing a 9.35 mm wide opening. The cove bit is 12.7 mm (1/2") diameter and is used with a 16 mm guide bush, producing a 13.7 mm opening. In practise of course, none of those dimensions will be anywhere near that precise, but that was the aim. For reference, the element coil is a little over 13 mm diameter.
Routing out the groove was a bit of a plod as I had to keep moving clamps and cross-bars. For the first pass (with the straight cutter), I fitted the vacuum attachment to the little trim router, which worked remarkably well at catching most of the dust produced (I still had the respirator on just in case). This photo shows how it looked part-way through routing the slot...
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... and this one shows the straight slot finished:
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For the work with the cove bit, I got rid of the vacuum attachment (but kept the respirator on). That was partly because there would be less dust produced in this step, but mostly because I couldn't remove the router from the slot when I was moving the cross-bars around and the vacuum hose would have been a bit unwieldy (with it attached, I couldn't have just left the router sitting in place while moving the bars around as the weight of the vacuum hose would have pulled the cutter straight through the fire brick).
Anyway, it didn't take that long to go all the way around the groove. There were quite a few little breaks, resulting in a rather shabby edge, but it worked better than I thought it would (I didn't have very high hopes for this process!)
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I haven't tried feeding the wire all the way round yet (as it still needs stretching out a little more), but I did a quick test fit and it went in relatively easily:
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Yes, I think you're right.Looking good! I think its going to mighty fiddly working that element around the bends!![]()
I'm sure it is, but I'm trying to hide the evidence of my welding, not show it off6013 in 1.6mm is a good filler![]()
Filler will attract moisture so needs to be painted soon after, and effort to sand it smooth after. Im not sure builders filler would stick well to metal, so would choose the 2 part car stuff. Also more of a pain if additional welding needed in future.
I won't be spraying it, partly because of not really having a good place to do so, but mainly because my results with spraying have never been that much better than my brush results.The problem currently is cold weather, its not going to spray well or dry properly outside. I have a couple parts waiting and cant have solvent smell indoors - I'll warm the spray can in warm water and the part with heat gun, then into a sealed plastic box to dry indoors for a couple hours.
I've made a decision that I'll probably come to regret in a week or so. I'm going to paint the control cabinet (inside and out) before trying to wire it up. I detest painting (hence the comment about expecting to regret it), but I think it's a necessary evil in this case as it'll get stored in a lock-up rather than in my relatively dry garage and hence could be at risk of rusting.
I've ordered some general purpose metal paint for the control cabinet and some (relatively) high temperature paint for the chamber metalwork. That should all be here later in the week, so I'll probably grimace and get the brushes out next weekend.
I've made a decision that I'll probably come to regret in a week or so. I'm going to paint the control cabinet (inside and out) before trying to wire it up. I detest painting (hence the comment about expecting to regret it), but I think it's a necessary evil in this case as it'll get stored in a lock-up rather than in my relatively dry garage and hence could be at risk of rusting.
I've ordered some general purpose metal paint for the control cabinet and some (relatively) high temperature paint for the chamber metalwork. That should all be here later in the week, so I'll probably grimace and get the brushes out next weekend.
It did, however, get me thinking about the sheet-to-angle joints on the various parts of the cabinet, both outside:
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and inside:
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I'm wondering if it might be better to fillet those corners with a bead of something-or-other before painting it. I'm thinking of the look of a silicone sealant bead around a bath, but not in silicone, obviously.
What would be a good option for this? Car body filler (which I've never used before) seems an obvious candidate given I'm trying to fill a gap in some metalwork, but would something cheap and easy like decorator's caulk work? Is there a better (for which read "easy to apply") option anyone can suggest?