Making and using a Shellac Chuck.

[Tony Bird]

Hi,

Every year I give a talk to the local model engineering club. I was apprenticed in the Horological trade where we used Shellac Chucks; some times known as Wax Chucks. As far as I know these chucks aren't used outside the watch/clock making fraternity. When I started model making and using larger lathes I had to make my own chucks as as far as I know none are available commercially. They are quick, simple and cheap to make.

Shellac is a natural resin secreted by the female Lac beetle, it is refined and has over the years had many uses electrical insulation, gramophone records, varnish and a food glaze to mention only a few as well as being a glue. Shellac melts at 84 C and can be dissolved by methylated spirits (ethanol).

I have always thought that using Shellac Chucks is much like using a Micro-wave cooker. They can do things that others can't, do similar jobs and not do others. So Shellac Chucks have limited uses but far more than you would expect.

The attached video shows the making and using the simplest of Shellac Chucks which I made as part of my talk. The more complex chucks and mandrels will be in a Power Point presentation using still photographs.

The video is my first attempt at filming workshop operations so is perhaps a little long.

I hope you enjoy and maybe learn something. It you try making and using one USE SHARP TOOLS and DO NOT TURN HOT!

Regards Tony.

 

[goldstar31]

Tony.
I'm a bit lost. As you w ill probably read in my replies to Bazmak, I bought two sets of soft jaws for my Sieg C4 lathe and a couple of cakes of beeswax from Axminster Tools. The latter were to mix with shellac pellets which I bought earlier from Axminster. Prior to your process I intended to mix the shellac and beeswax 3 to 1 following Tubal Cain's ( T.D. Walshaw's) recommendations.

OK, I have no sound( I'm deaf anyway) but would like clarification on 'your glue stick' I've used this intended sticky concoction probably from doing sanding and emery stuff on face plates-- years ago.

So I'd appreciate a bit more detail from you about your resins for this variance, please




Thanks

Norm

 

[Tony Bird]

Hi Norm,

I have never used shellac other than straight from a stick, do you know of any benefits in mixing it with beeswax? The shellac I use comes from the horological suppliers cousinsuk.com it is in I think the consumables section. The refined stick shellac which I use is used to hold pallet jewels in their pallets as well as on chucks. There is another form which comes in discs and is usually very dark which is used in jewellery work, I have never tried it on a chuck.

Alas I haven't read Mr. Walshaw's recommendations on its use or you correspondence with Bazmak. Being brought up so to speak using shellac chuck there is rarely a model that I have made where they weren't used several times.

If I can help further please ask.

Regards Tony.

 

[10K Pete]

What's that horrible clattering noise when the lathe is running? And, yes, the video does run quite a bit long.

Shellac chucks are very handy and not well known these days so thank you for showing how to do it!

Pete

 

[goldstar31]

Thanks Tony
Initially for what you actually use and also for a note of your supplier. Mine was--very expensive!
It was in pellet form and probably used with methylated spirits on grand pianos for French polishing. You know a linseed oil rubber and when all was said and done a 1911 Bluthner 7/8ths Grand was offered at a cool £19000!
How do I know? A wedding anniversary present! My daughter has it now.

So I actually had no idea of using shellac -neat- apart from French polishing. Walshaw was a lecturer in engineering at Darlington and obviously was a prolific designer, machinist and author. With a semblance of doing things like the esterification of fatty acids and modifying gum rosins, I assumed that Walshaw was using beeswax as a plasticiser instead of such things as a better alternative to the cheaper paraffin wax and the more expensive camphor.

And really, Tony, I was following in the steps of a master- somewhat blindly. Your contribution has now given me food for thought.

Thank you

Norm

 

[Tony Bird]

Hi Pete,

What's that horrible clattering noise when the lathe is running?

The Myford has two belt drives one of which is starting to break up. I am hoping to replace it with a belt that can be joined. Oddly some times it is silent!

Regards Tony.

 

[Nick Hulme]

Or you can just face a chunk of what you have and use an activated mitre bond cyanoacrylate, I use a Wickes branded mitre bond, heat sensitive parts can be removed by soaking in Acetone.

 

[Nick Hulme]

What's that horrible clattering noise when the lathe is running?

I had to turn the sound off and then still couldn't watch knowing basic maintenance was required and was being ignored.
Just fit the correct belt, it isn't difficult and doesn't take long!

 

[Tony Bird]

Hi Nick,

Or you can just face a chunk of what you have and use an activated mitre bond cyanoacrylate, I use a Wickes branded mitre bond, heat sensitive parts can be removed by soaking in Acetone.

I have used similar products and they work real well. Its habit and the fact that shellac allows you to adjust the work piece's position for centring etc that I mostly use it. Because of its low melting point the work piece can be removed from the chuck by boiling in water.

I had to turn the sound off and then still couldn't watch knowing basic maintenance was required and was being ignored. Just fit the correct belt, it isn't difficult and doesn't take long!

I couldn't agree more but alas to replace the one belt on a Myford S7 the headstock and counter shaft have to be stripped. having done it once some years ago, it took a many hours and wasn't easy, so I am waiting until we visit our daughter in a few weeks as there is a place near her that sells belts that can be joined to any length. I am a bit deaf and I don't think the belt is doing any damage due to its state.

Regards Tony.

 

[Hopper]

Haha, you sound like me. (no pun intended but all kudos accepted) If I wear my hearing aids on any of my old motorbikes the rattling scares the daylights out of me. Taking out my hearing aids is much easier than rebuilding engines so is the preferred method!

 

[10K Pete]

Tony, have you considered using segmented V belts? They can be installed without stripping the headstock. My SB 10K originally came with a continuous belt that had to be cut to get it out of the machine, and re-glued to put it back together. I replaced the flat belt with a Fenner Power Twist segmented belt (and the appropriate V belt pulleys). The machine runs quieter and smoother than with the flat belt. I have the Fenner belts on most of my machines and won't go back!!

Cheers,
Pete

 

[goldstar31]

I got mine from RDG Tools. Probably not the cheapest but it came by return of post.
It's still not been fitted but I'm one who has an almost unmentionable mark1 Myford Super 7B with its round sight glass and and an impossible clutch. Still it is slideways ground and has a Turcited under saddle which corrects all the tramlines of an earlier existence. With tongue in cheek, the old rattle trap is probably more accurate then when it came out of the Myford factory.

It's got all the noisy needle bearings-- or so I'm told. Unbolted ,it falls over like me when I'm on my 4th large glass of Vino Collapso .


N

 

[ozzie34231]

By using a hot glue gun, or super glue you can eliminate the first heating process.
I see that some are using masking tape on both the chuck and workpiece and then super gluing together. It holds good and makes cleanup easy. The process can be used on both lathe and mill.

 

[Tony Bird]

Hi Pete,

Tony, have you considered using segmented V belts? They can be installed without stripping the headstock. My SB 10K originally came with a continuous belt that had to be cut to get it out of the machine, and re-glued to put it back together. I replaced the flat belt with a Fenner Power Twist segmented belt (and the appropriate V belt pulleys). The machine runs quieter and smoother than with the flat belt. I have the Fenner belts on most of my machines and won't go back!!

Yes that is what I intend to fit, a number of my machines use them, I have a length which isn't quite long enough and hope to buy the same brand when in London .

Regards Tony.

 

[Anatol]

Thanks Tony
that's an interesting technique utilising the easy meltability of shellac. (I thought you could melt it with an electric hotplate too. A bit slower but no burning. I was wondering if you couldn't do it also with an appropriate wax - maybe beeswax which is a bit sticky (might have insect resins in it, like shellac. ) I guess the soldier idea previously suggested is much the same.

 

[BaronJ]

Hi Guys,

Hot melt adhesive works in exactly the same way ! And it is cheap, very cheap.
The commonly available sticks can be bought in Aldi for about £3 and a whole kilo of the type that they use to glue cardboard cartons together, for less than £7. This latter type comes in pellet form, it is quite soft and flexible, and is very useful for securing the ends of abrasive belts. A single pellet and a hot iron works well on a 20mm belt.

 

[goldstar31]

I've been getting conflicting reports about these sticks and having had Aldi stuff fail, I went to Loctite sticks but I have yet to experiment. I do like the suggestion about joining transmission belts but I have no immediate need.

Most interesting

N

 

[BaronJ]

Hi Norman,

Unfortunately there are several different types of hot melt adhesive. Some are quite hard and rigid, whilst they all will work to secure belt joints, the ones that rapidly fail are the ones that set hard, becoming quite rigid. The joint tends to break up when going around the rollers. The smaller the roller the worse it is.

I've just done a couple of 20 mm wide belts that run around a 10 mm diameter roller. Double sided tape from Poundland worked for a little while.

Now the pellets that are intended for joining cardboard cartons and the like are quite soft and are very flexible. These are also the best type for so called "Wax Chucks" The heat required is of a similar order to that of shellac.

 

[fcheslop]

Having tried many cheopo alternatives I now stick to shellac or super glue
Not much fun when the glue fails and the part wizzes past youre lugs never to be seen again
Just my two bobs worth
cheers

 

[BaronJ]

I couldn't agree more ! But like all things, there are many different varieties !