CA Application Question

[magpens]

I think I have been reasonably successful, in general, in developing a method for CA finishing.

However, one aspect continues to bug me.

I turn between centers, using steel cones in both headstock and tailstock, and I use those when sanding and finishing also.
When applying the CA, I drip the CA from the bottle, held above the very slowly rotating blank.
At the same time, I lightly rub the underside of the blank with polyethylene sheet to distribute the CA over the blank.

The CA always gets onto the steel cones and tends to bond the blank to the cones at both ends.
After applying a few coats of CA, the nicely shaped blank is well and truly stuck to the steel cones.

Therein lies the problem ... because getting the blank unstuck from the cones sometimes damages the CA finish.

I am wondering if I should machine some polyethylene cones to replace the steel ones. . CA does not stick to poly.

Any suggestions would be appreciated. . . Or any alternative ideas ?

If you think that polyethylene cones would be a good idea, where would I buy some poly rod to make cones from ?

 

[Pierre---]

I would say the first thing would be to practice on how to "take off" with your polyethylene sheet when reaching the end of the blank, so that a minimum CA bead is on the blank, but not on the cone.
Poly cones would not hurt, I use and love them because I can adjust the shape so that they stay away from the blank edge.

 

[Bats]

Have you tried giving your centers a coating of paste wax? My current application method doesn't usually leave enough behind to glue the blank to the centers (although it does tend to glue the bushings on, when I use a mandrel), but it still does tend to leave a mess, and the wax makes it easier to peel off.

As for the cones, McMaster-Carr has UHMW rods as well as Delrin and Acetal rods in a wide range of sizes.

 

[CjG78]

Mal I tbc my tubes when making kits, when it's time for ca I use a pen mandrel with hdpe bushings rubbed with boiled linseed oil, never had one stick since. I apply a few drops to paper towel and lightly rub in several times.

 

[magpens]

Mal I tbc my tubes when making kits, when it's time for ca I use a pen mandrel with hdpe bushings rubbed with boiled linseed oil, never had one stick since. I apply a few drops to paper towel and lightly rub in several times.

Thanks, Casey. . . I don't use mandrel or bushings. . I believe that BLO does not affect CA, so I suppose I could rub BLO on the steel cones.

Have you tried that ? .... and what would you think of that idea ?

 

[Jans husband]

Mal,
You always ask for photos, so now its my turn to ask for photos and further details of the steel cones you use and possibly a link to a Vendor. I turn between centres rather than use bushings SOMETIMES, and I thought from previous posts you have made in different Forums that you used an abrasive cone for the centres (to give adherence to the tube being turned)

It may be that a steel cone is called something different on this side of the Pond, so I am hoping a reply would clarify things for me.

I also use hdpe bushings when applying CA finish, which is not very often, and wipe them off with DNA after use.

Mike

 

[magpens]

Mal,
You always ask for photos, so now its my turn to ask for photos and further details of the steel cones you use and possibly a link to a Vendor.
Mike

Thanks, Mike. . . The tailstock cone ( prob. about 60 degree ) is a standard live center cone on a MT2 mount ( to match the tailstock ).

You mentioned the abrasive cone that I use in the headstock when doing the blank turning ..... you have a good memory !!!
I use that cone ONLY for turning. . Would never use it when applying CA, for the obvious reason.

When applying CA, I use a steel headstock cone that I made from a 3/4" steel rod ..... 20 degree ( or so ) included angle.

My photo capabilities are poor ( no cell phone; bulky OLD 35mm SLR ), so I am hoping you aren't serious in asking for photos of these cones.

I favour the conical shape and I never use mandrel + bushings, so I am not inclined to buy HDPE bushings of the kind to which I think you refer.

I would, however, make HDPE cones for my required purpose of applying the CA finish.
It is just a matter of finding a source for HDPE rod from which to turn them.

 

[Jans husband]

Thanks Mal,
I remember your use of the abrasive conical centres very clearly, and I recall at the time you had a link for the Vendor.
In respect of HDPE, buy a white chopping board of the the same material for a few dollars, use your saw to saw off strips and make them from there.
Only an idea!! I've not done it myself, but may give it a try. You could make hundreds from one board.
I recently bought a couple of Beech rolling pins in a sale at a well known UK store, and made 6 salt and pepper pots for next to nothing cost of materials.

Mike

 

[magpens]

Thanks Mal,
I remember your use of the abrasive conical centres very clearly, and I recall at the time you had a link for the Vendor.
In respect of HDPE, buy a white chopping board of the the same material for a few dollars, use your saw to saw off strips and make them from there.
Only an idea!! I've not done it myself, but may give it a try. You could make hundreds from one board.
I recently bought a couple of Beech rolling pins in a sale at a well known UK store, and made 6 salt and pepper pots for next to nothing cost of materials.

Mike

Re the abrasive cones .... they are mortise chisel sharpening cones from the Lee Valley retailer in Canada. . Probably avail elsewhere.

https://www.leevalley.com/en-ca/shop/tools/sharpening/files-and-hones/100265-large-cone-sharpeners-for-premium-hollow-mortise-chisels-and-bits?item=77J8122

Your suggestion re using an HDPE chopping board would seem to imply gluing the strips (or segments) to make a bar and then turning the bar.
What glue to bond polyethylene ? . . .

 

[KenB259]

I bought a 1 inch acetel/ delrin rod on Amazon and I make my own finishing cones.

 

[magpens]

I bought a 1 inch acetel/ delrin rod on Amazon and I make my own finishing cones.

Thanks, Ken.

I see that Delrin and Acetal are probably trade names for Polyoxymethylene (POM) .... which I never heard of until today.
Maybe I'll be able to find some. . I thought I would be looking for Polyethylene, but I guess anything that doesn't "stick" with CA will do.

There are millions of different plastics, so there must be something !! . . Should be able to find one to do the job.

Keep the ideas coming, everybody !!!

 

[Bats]

I see that Delrin and Acetal are probably trade names for Polyoxymethylene (POM) .... which I never heard of until today.

Delrin's a trade name, acetal is a generic term, but, yep, it's all POM.

Confusing the issue, though, McMaster-Carr says "Delrin® acetal resin is also known as acetal homopolymer; it is stronger and stiffer than acetal copolymer." For our purposes, though, I think they can probably be treated as the same thing with different pricetags.

There are millions of different plastics, so there must be something !! . . Should be able to find one to do the job.

Two variants already mentioned that you might want to add to your search terms (I suggested McMaster before, but I seem to remember them being stubborn about shipping to Canada for non-business accounts - and the shipping would probably hurt even if they weren't) are HDPE and UHMW, which will probably both do the job - HDPE being High Density Polyethylene, and UHMW being Ultra-High Molecular Weight polyethylene. Why does one include "PE" in the acronym while the other doesn't? It's a secret!.

 

[MPVic]

I found this on Youtube by RJBWoodTurner on how to make TURN BETWEEN CENTERS NON-STICK BUSHINGS.

I made a set & they work great while maintaining perfect alignment of the blank you are finishing. These bushings made of Delrin or similar material, eliminate the sticking problem with CA.
The only trick I found is that you definitely need a drill bit with a 60 degree point so that the bushing will fit perfectly over the dead & live center points.

 

[KenB259]

The only trick I found is that you definitely need a drill bit with a 60 degree point so that the bushing will fit perfectly over the dead & live center points.

Stubby center finding bits are perfect for this. Countersinks will also work.

 

[Curly]

Mal I just use paste wax on the conical centres. The blank usually pops off no problem and I sand of the ends on a sheet of paper on the bench. Should you find the conical centres building a film of CA on them put a smaller diameter tube or drilled out rod between them. With power on cut the excess with a box cutter presented like a skew. Takes a couple seconds.

Lee Valley has 3/4 x 3" or 4" x a couple feet. Plastic World in Surrey and Langley have various bars, rods and sheets of all kinds of plastics. There is another plastic store off Mt Lehman in one of the industrial/warehouse buildings on the way to the Abbotsford Airport. Search around and there are lots of plastic and resin places in your area. Fiber Teck on Boundary might also have some.

 

[1080Wayne]

Mal , Industrial Plastics and Paints , Port Coquitlam . Their web catalogue is mixed up , but if you look under sheet stock and then under UHMW sheets , you will find UHMW rods from 1/4 to 6 inch dia .

 

[sorcerertd]

I also wax my centers and don't usually have trouble.

I do have a curious thought: CA does not stick to PE and pen parts come in bags made of PE. Any sandwich bag would be the same. I wonder if it is feasible to cut little pieces and cover the tip of the cones? I might have to test that out. Now, too much CA at once produces enough heat to melt the bags, this I know for sure.

 

[1080Wayne]

I also wax my centers and don't usually have trouble.

I do have a curious thought: CA does not stick to PE and pen parts come in bags made of PE. Any sandwich bag would be the same. I wonder if it is feasible to cut little pieces and cover the tip of the cones? I might have to test that out. Now, too much CA at once produces enough heat to melt the bags, this I know for sure.

CA may stick a bit to the printed side of a bag . That side has been corona discharge treated to improve ink adhesion .

 

[EricRN]

I use plastic bushes and haven't had any issues with sticking. I have, however, had an issue with water getting underneath the CA finish layer while I wet sand and cause it to pull away from the blank or turn cloudy. Anyone else experienced this and found a good fix?

 

[Bats]

I use plastic bushes and haven't had any issues with sticking. I have, however, had an issue with water getting underneath the CA finish layer while I wet sand and cause it to pull away from the blank or turn cloudy. Anyone else experienced this and found a good fix?

I know that some people will seal the ends of the with CA after squaring the blank (put a few drops of thin CA on a folded paper towel, then wipe the end of the blank on it). My usual barrel trimmer is smaller than a lot of the blanks I use, which makes that difficult, so sealing the ends after turning is a better option for me. Except that I usually forget until it's too late. If it survives through the sanding process, I usually seal the ends afterwards anyhow, in hopes of preventing future issues with humidity in the atmosphere, or humidity when someone drops the pen in the toilet or runs it through the wash.

 

[aRMdaMAN]

Mal I tbc my tubes when making kits, when it's time for ca I use a pen mandrel with hdpe bushings rubbed with boiled linseed oil, never had one stick since. I apply a few drops to paper towel and lightly rub in several times.

Hello there CASEY
Brilliant !!! Now why didn't we think of that !!???
Kudos to U
Definitely gonna try that on my next pen
Thanks a zillion
ATB
TC
aRM

 

[howsitwork]

i just e bayed for HDPE rod , here's the uk answer

Plastic HDPE Rod Natural Bar 10, 12, 15, 18 & 20mm Dia 50mm up to 600mm Long | eBay

50mm (sample), 100mm, 150mm, 200mm, 300mm & 600mm. HDPE – High Density Polyethylene Round Rod/Bar - Natural. HDPE has the following properties Chain sprockets. High tensile strength. Available in lengths of.

www.ebay.co.uk

thats for 16 mm diameter by 150mm long should be enough. Whilst you're at it make a tapered tube insertion tool for good measure!

 

[foursquare]

Mal
This should work for you: https://www.amazon.ca/Molecular-Pol...p_85:5690392011&rnid=5690384011&rps=1&sr=8-19