What is better than Shellac ?

I have used shellac for temporary holding jobs, but I'm sure that there must be better stuff now. I would appreciate your advice.

Basically, to hold parts for machining and then to release them easily again, using moderate heat, solvent, whatever.

Regards, Tim

I have used super glue on occasions, but depends on the area available for adhesion and the job in hand.

Superglue or double sided carpet tape.

Strangely enough I had to do just that this afternoon, I was making a 0.5mm thick thrust washer and to get an accurate thickness after parting off from the parent stock I glued it with superglue to a piece of scrap bar held in the chuck. After the thickness was finished I removed it with a heat gun.

I suppose I could have used a flame but I didn't want to risk distorting it with too much heat.

Phil

I wonder if threadlock compound would give enough grip on flat surfaces. I use it to hold 1/8" cutter shanks in silver steel shafts in my Roland engraver (reamed hole, so close fit), and it lets go with mild heating. The extra area holding, say, a washer should give it a fair bit of grip as long as there is a close fit.

Using double sided tape is very effective, but gives an unknown and uncontrollable distance between the workpiece and its holder, so is not ideal for precision work.

George

PVA glue on the faceplate or whatever, then a sheet of thick drawing paper, then PVA and then your part, clamp up, leave to dry and it resists quite a lot of force.

Boiling water cleans it all off.

Hot melt glue ?

I use Loctite on my wax chucks. You apply  heat with a small blow torch to burn it off when you are ready. I use Loctite 263, the high strength red one.

WARNING : it sets very quickly  but I give it 24 hours before machining it.

Edited By Brian John on 04/12/2015 05:56:14

The method mentioned by JS will hold quite a load, when I was wood turning I used that method when making large bowls, mostly 9" diameter by 4" deep Mahogany, the base of the bowls were usually about 4" diameter. Instead of soaking it in water, a chisel at the joint, a sharp whack with a mallet splits the paper, then a damp cloth takes of the remaining paper and glue. I'm not sure of the weight of the wood, but the blank I started with was a square bit with the corners cut off, and you don't need to go gently when you get working on it.

Ian S C

Ian,

I used to do the same, just had to be careful when you reduced the diameter of the bowl base if the bowl was a large one!!

True! I tried to make my gluing area the right size for the finished base, then I didn't get the tool in the joint area. I usually could get two or three small bowls out of the large one(waste no want not), to make these you must dig deep into the face of the bowl blank, then hit it hard with a hammer, and the waste bit breaks out, and you can finish that later, but the glue paper glue still holds(I think one came unstuck).

Ian S C

Thanks for all your helpful responses. So can I summarise?

Shellac is not super strong, separates with heat, and cleans off easily with alcohol

PVA is stronger, best used with a paper interleaf, then separates with impact, and cleans off with boiling water

Loctite (et al) comes in varying strengths and viscosities, separated by heat (hotter than shellac but not enough to destroy temper) but removed with difficulty.

Superglue is similar to Loctite, needs more careful use.

All I need for perfection is a solvent for Loctite and Superglue traces after separation. Acetone? Formaldehyde?

Regards, Tim

Old fashioned Nitromors paint stripper shifted loctite, but I've been told they have reformulated it so not sure whether the new stuff does. The active ingredient was dichloro methane, but it is wicked stuff, very volatile and carcinogenic.

Loctite Detach removes Loctite (as the name suggests), and there is a similar thing for Superglue (which I have used on my fingers once or twice.....). They are commercial products, but designed for the job.

The superglue remover is supposed to live within arm's reach of my bench, but I can't see it at the moment, which is a bit worrying.

Marcus

I use acetone, cheap and easy.

acetone( nail varnish remover) works , leave it to soak and the superglue either rubberizes ( softens ) or dissolves off.