Thread: Straightening a monkey tail

I have a vintage razor that is slightly harder steel than modern Dovo's (based on it's higher pitched tone when twacked with a fingernail). The monkey tail tip contacts the scales unless I close it extremely carefully.

Will bending the monkey tail cause the tang to crack ? (Are the tang's hardened ?)
Is annealing the monkey tail with a $20-30 propane soldering set-up likely to work ?
The scales are a hard cream colored plastic. Is there an easy way to repair the flea-bite that the monkey tail took out of the edge of one of the scale ?

Thanks.

My guess is that the razor is pinned on a skew. Either incorrectly to begin with or perhaps it was skewed when someone tightened the pivot pin ? Anyway, AFAIK if you attempt to bend the monkey tail you'll risk breaking it. I personally would just close it carefully. I have no shortage of razors that I have to close with care because they are tight when open but get loose as they close. Someone that knows what they are talking about may be along though.

Will bending the monkey tail cause the tang to crack ? (Are the tang's hardened ?)

Not always, but there's a serious risk.

Is annealing the monkey tail with a $20-30 propane soldering set-up likely to work ?

Yes and no. It will almost certainly work because annealing steel is pretty easy to do. The problem is trying to do it without ruining the temper of the entire blade. I don't know if it's even possible, but it's certainly not easy.

The scales are a hard cream colored plastic. Is there an easy way to repair the flea-bite that the monkey tail took out of the edge of one of the scale ?

If it really is a flea-bite sized imperfection, then sand past it and polish everything back up. As long as you go by hand and don't let it heat up, it's relatively easy to sand and polish.




A more sensible approach, if it's 'just' hitting the scales, would be to unpin the razor, and re-pin it with extra washers to spread them just a touch.

How bent is the tail?
Yes you could crack or break the tang, but more than likely you would break off the tail before the tang broke.
Annealing is not quite as simple as it sounds unless you have a way to get it really really hot, like ~1700 degrees, when the steel turns a yellowish hue in the fire or when a magnet no longer sticks, this is the critical temp when the steel changes on a molecular level from very hard martensite back into austenite. Do not quench after this temp is reached, leave the blade in a bucket of sand to cool slowly. Doing so would of course erase the temper because you have changed the carbon structure of the steel. Annealing would make the steel soft enough to shape, but then you need to heat treat it again, which is even more critical than annealing. You have to get the steel back up to the critical temp ~1700, then quench in hot oil (stand back, there will be fire). Now if the blade does not crack or warp when you quench, which does happen, you now have very hard and brittle martensite again. You'll have plenty of black flakey formations on the surface of the steel that will have to be ground off. This now needs to be tempered to remove the levels of the very brittle martensite, 400 degrees in your oven for an hour will take care of that. Now you will need to clean up the blade, because you will have discoloration from the heat treat and temper. Heat treating is tricky because too many heat treats stresses the metal and you could end up with a softer steel after temper, also if you temper too much you'll remove too much martensite and it will cause it to be too soft.

Not to discourage you too much, but will a $20-30 kit get your steel to critical temp? It could, but my experience says unlikely. You need to get air to it to get that steel where it needs to be to anneal.

I have bent hardened tangs. I put the blade portion in a big vise (heat sink) and put a ring of this stuff heat block where the tang meets the vise. I then use a propane torch and heat it up till its is just barely dull red then bend the tang with a adjustable wrench. I would say this methods works 90% of the time. I have broken a few but not many.

Charlie

Originally Posted by spazola

I have bent hardened tangs. I put the blade portion in a big vise

+1 put it in a vise use the 3 rod method, and gently push it using the vise alone, I have done quite a few this way, I have seen where other's have broken tangs this way but have not experienced this myself...
The older and thicker grind the razor is, the more likely the tang is not near as hardened and the blade is

The biggest hint I can give here is don't get carried away, honestly we are talking moving thing a very little amount to create clearence..

Also search out Spazola/Charlie's threads on adjusting the tilt of the razor between the scales, he did an excellent diagram using graphics on how we move them with very simple use of a file

I think this is the one gssixgun is talking about http://straightrazorpalace.com/works...centering.html

The tang is most likely hardened, but perhaps not as hard as the blade. You shouldn't try to bend it in that condition. Even if the tang has been bent by an accidental blow, that may be all the bending that particular piece of fairly hard steel will stand.

You don't have to raise the temperature to anywhere near the critical point, to anneal steel. That is only needed to harden it. While slow cooling from cherry-red will anneal the steel, plain carbon steel will be just as well annealed for the present purpose at 650 degrees fahrenheit. Its critical point, incidentally, is likely to be around 1400 fahrenheit, and yellow hot at 1700 fahrenheit both causes surface scaling and risks reaching the temperature which will burn carbon out of the steel.

Blue Blade Steel spring - steel, hardened and tempered steel, annealed

Heat & Temperature

With most steel objects, the part you want to remain hard can be clamped between pieces of copper sheet in a vice. You should do this with caution with something as thin and hard as a razor, however, since hard pressure may break it, particularly at the pivot hole. I'd hold the blade in water up to the pivot hole, and then use, on the tang, one of those little torches you can fill from a lighter butane canister. When the colour changes from dark to pale blue, it should be bendable. B

You don't say whether the tang looks in line with the spine, in which case I would look for a solution in the scales. Annealing requires removal and reattachment of the scales, and you might find bending of these and perhaps adjustment of the rivet holes to be a better option. Otherwise, very careful closing is a course worth considering.