I've subscribed here to ask if there are any machinists who could manufacture for me a set of simple punches for punching discs out of 4mm thick pressed felt (fairly soft)?
I need to make well-cut discs of felt in small quantities, in a number of diameters ranging from 10mm to approx 80mm, but I don't need a long-lasting, expensive tool. It's really expensive to buy a whole load of professional wad punches, so the alternative is perhaps to machine some simple punches out of bar stock. I just need something with a sufficiently sharp ring edge and a back surface I can whack with a mallet - or even use with a small, bench fly press if I were to find one.
Is there anybody here who might be able to help?
Please remove the "spamwitheggs" from my email address - it's fsnet.co.uk at the end!
The thing is, I need 31 different sizes! I only found one supplier who does an extensive range from 5mm to 75mm in 1mm increments (and an Imperial equivalent set), but the prices range from £15 to £100 for each single punch!
Thanks! I'll drop you an email. Hmmm, if you can run something up, I don't suppose you might then time over the next month or so to make more, of different sizes? Having no facilities, I really can't do it myself, and it would be absurd to spend £1000 at the supplier I mentioned!
What range of diameters of silver steel (or anything else) stock can you get in small enough quantities?
-Please remove the "spamwitheggs" from my email address
Another option would be to make up an adjustable cutter by attaching a scalpel holder onto a pair or lockable calipers.
I'd recommend using the Swann Morton No.10 blade ( with a curved edge
- the straight-edged blades would tend to snag ) and its corresponding holder. The business end of the holder could be cut off and silver soldered to the end of the caliper, with a lay-back of about 20 degrees to maximize the cutting edge presented to the felt
This tool would give a sufficiently neat cut for your purposes, and has the advantage of being infinitely variable within its range. You'll need a fair few blades though - thick felt tends to blunt scalpels very quickly, and they're a chore to sharpen.
I just tried out a lash-up version using one of those cheap plastic compasses that has a pencil holder - and it works, even on woven felt ( which is much harder to cut ). You'd need to ensure the blade was set so that it remained largely upright otherwise it would cut a tapered disc ( which wouldn't be too much of a problem for 4mm felt ). This would be done by altering the length of the caliper legs...so a pair with an adjustable pin would be a bonus. The lockable function is a must - even the light pressure you need to apply to the blade is enough to push the caliper apart.
In fact, it works that well I'm going to knock up a pucker cutter for my own use... 'cos there's always those times when you need a disc half a mill larger or smaller than any punch you own.
Yes, I'd wondered if that might be an option. I haven't got any silver solder facilities, though.
It's not practical for the smaller pads, but cutters/punches are of course more easily found for those diameters.
Could you let me know if it works well? I'm off on holiday for a week shortly.
Talking of solder, Stephen, I'm busy overhauling my Conn virtuoso deluxe alto. Gawd, it's had some real vandalism! The two posts for the low C# have been resoldered - it looks as though they may have been knocked off in an accident. The solder work is really clumsy. Not only that, but the thug who did it put back on the lower post back-to-front! Moron! And whoever resprung it last (using ugly stainless wire rather than tapered needle springs) didn't half jam the blighters in - all the larger holes are massively widened by the flat ends of the springs. He must have driven them in with a sledgehammer. It's causing me a real headache to shape some new needle springs to fit properly. Vandals!
Can you silver solder posts back onto a gold-plated horn without acres of solder bulging out around the base and ruining the finish?
I like to slum it every now and again! Actually, there's some seriously knowledgable folk here - and the usual 'others'.
OK, you could soft solder it at a pinch, or if even more desperate, wire the thing on and beef it up with epoxy resin.
Absolutely - I reckon the minimum diameter would be in the region of
30mm...but then that's with the crappy lash-up...a stout tool might well be more adaptable.
If I get it done in time, sure - I'll have a trawl around town and see what's available. If I can find two, I might well knock something up for you!
It's a real pain when those holes get widened. If you're very lucky you can persuade a larger than normal blued steel spring to behave ( kinking it is always a good bet ). Otherwise it's acceptable practice to use a small portion of another spring as a wedge. Provided it, and the main spring, are fitted well enough they're unlikely to fall out. Other than that you either have to fill and drill the existing hole, or drill a whole new one ( but that can get complicated with respect to the angle of the spring ). It gets to be a tough job without the aid of a pair of proper spring pliers though.
They won't be silver soldered on - if you try to do that you'll find pillars dropping off all around you! Soft solder is the stuff to use - and the best way to avoid any excess solder is to ensure a snug match between the pillar base and the body. A good tip is to 'tin' the pillar base first.
This is simply loading the base up with solder so that you can place it in situ, heat the join and get a nice neat job with the minimum of cleaning up. Trouble is, it takes a bit of a practiced eye to gauge the right amount of solder to use. Never hurts to have a practice on a bit of scrap brass, bent to match the curvature of the body. It also means that you can't wire the pillar in place - so it takes a steady hand to hold the thing in just the right position as you heat it. Cleanliness is everything as well. Any oxidized areas and the solder just won't run.
Be prepared for a degree of mess - when trying to fix other people's soldering botches there'll always be a limit to how far you can undo their work.
I've managed to make do with the larger sizes of needle spring. It's hard work flattening the ends enough to make them fit, without the flattened portion getting so thin in the process that the sides are positively sharp!
Errm, what composition solder are we talking about, and how does its composition compare to electronics solder? Using a soldering iron is no problem - I used to do that sort of thing a lot when I was younger. I think the problem will be the heat - I'll presumably need a powerful iron with all that metal mass conducting the heat away. I'm also not sure if I would get an adequate joint if I were to tin both surfaces first but then only apply heat and more solder to the post (thus avoiding damage to the body) before quickly joining.
So I *must* join the surfaces and *then* apply heat? No other option? If that's the case, do you use an iron, or a flame?
Heat the end to red hot to anneal the steel - makes it easier to flatten out the tip and prevents it splitting. Be careful not to heat too far along the spring or you'll ruin its effectiveness.
Opinion varies as to the best composition - some manufacturers use a
70/30 mix of tin/lead, other 60/40 - some use 50/50. Most electronic solders are 70/30, I think. High tin content improves the 'wetting' ability of the solder, so they're a good bet for maintenance work. The more tin, the lower the melting point ( average 360 deg F ) - though this isn't really an issue for our purposes. Bog-standard resin cored solder is fine for most purposes - though I'd strongly recommend using a decent flux ( the core flux is pretty useless for this application ). LA-CO regular soldering flux paste is superb, pick it up at any plumber's merchants. Clean the joint afterwards with a solvent ( good old lighter fluid does the trick! ).
I find lead free solder to be rather too brittle, needs a higher temperature to flow and it doesn't have the same workability as lead based solders.
You won't have much luck with a soldering iron - it's time to invest in a gas gun! A proper setup ( gas bottle, hoses, regulator, gun, nozzles etc ) will cost a small fortune ( but will last almost forever ), but you can get a long way down the road with a portable flame gun ( I sometimes use one myself, when the local garage runs out of calor gas refills ). Primus make a decent one, though if you have the cash Sievert kit is better. An electric iron just doesn't have the necessary heat throughput and always results in a poor job.
Either you tin the pillar base first, or you place the pillar in position and feed the solder in - either way you have to apply heat to both the pillar and the body at some point, and that's where you'll certainly need a flame gun.
Not expensive, and not scary hi-tech. For small items, (thin sheets) a plumber's blowtorch from B&Q and a couple of bricks to sit the work on do quite well. Silver solder (NOT silver-bearing lead solder) and borax flux (powder) used to be available from Maplin - if they have stopped, there are other sources, Chronos comes to mind.
Don't practice on a musical instrument...
Torch, 1 oz borax, a couple of silver braze rods, emery/brasso should come to about 25 quid... There are better rigs, but even this lot is better than no facilities.