Brass Tube Sanding on lathe

[LeeR]

This may have been covered before, but I did not find it doing a quick search. I use my old pen mandrel with Delrin bushings to sand and finish blanks. After sanding a few brass tubes by hand the other day, I decided there has to be an easier, more uniform way.

I just use the same setup as I do for finishing. I use really fine sandpaper, since they clean up very fast.

 

[Rodnall]

OK, here are my personal thoughts on tube sanding. I hear about people sanding them on the lathe but I don't believe that's the best way to do it. My belief is if you use a very coarse sandpaper or emory paper and put lots of pressure on it as you rub it across the tube, you will put bigger scratches in the tube resulting in more of a bite for the glue to hold on to. But that's my opinion and there could be other reasons not to do it my way.

Rod

 

[Jim Burr]

Nice setup Lee! I'm not sure uniformity is s concern over making sure the entire thing is scuffed....IMHO!! I put them over a pencil and hit it with 100g on my ROS. 2k pens and I keep trying to improve how I do things. The ROS seems to give me great scuffing over the entire blank, but again, uniformity hasn't been my goal.

 

[hard hat]

That's a good looking setup Les. I used to sand mine on the lathe with 120 grit, just enough to get the nice spiral down the length of the tube. I realized that I would do it with less fiddling with the lathe if I used the 1x30 belt sander. I hold the tubes by hand, get one end the get the other. Works really well and it's fast. Not that speed is important, I just don't like changing the lathe setup often

 

[PenMan1]

Why do you sand pen tubes? Are you going to paint them? If not, sanding brass tubes actually causes glue failures with both CA and Epoxy glues.

 

[LeeR]

I should have explained my primary reason for this. I am not a seller so I am not looking for the most efficient way to do this -- this method does require a little more setup. In the past I would sand around the rings, to basically create rings or ridges to provide more grab. But at times I felt like the gaps were just too great. Some of this was a lousy drilling process using my drill press, and getting probably more oversized holes than would be typical. I switched to drilling blanks on the lathe, using the new Nova Pen Drilling jaws on a Nova Midi chuck.

My goal was to get a really smooth, and close, fit between tube and blank. Besides drilling on the lathe, I recently started drilling with undersized bits, as well. For example, I'm using a Z bit instead of a 27/64" bit on a Virage kit. By having a pretty close fit between tube and blanks, a minimal amount of adhesive is required, whether epoxy, polyurethane glue, or CA.

 

[kovalcik]

I used this type of setup for some tubes I wanted to polish up for a casting project. I wanted the shiny brass look for the background, so I went throught all the MM pads. Came out like a mirror. It is a great way to hold them.

 

[thewishman]

I quit sanding tubes years ago.

 

[avbill]

Andy Why does sand brass tube produce failures?

If not, sanding brass tubes actually causes glue failures with both CA and Epoxy glues.

 

[BSea]

Why do you sand pen tubes? Are you going to paint them? If not, sanding brass tubes actually causes glue failures with both CA and Epoxy glues.

Why would it cause failures? I'm not trying to argue, just don't see how sanding could cause the bond to fail.

I've sanded, and not sanded, and I haven't noticed a problem either way.

 

[Wood Butcher]

I've done it both ways and had success with both. My understanding is that there is a film of some sort on the brass to avoid tarnish, notice the tubes in the kits stay pretty shiny. Sanding removes this and provides a little rougher surface for the glue to grab on to. It does this by increasing the glue surface just like a rabbit joint is stronger than a butt joint, more surface area.
That's what I have been led to believe.
WB

 

[PenMan1]

The brass "dust" from the sanded tubes contaminates the glue area and can cause the glue not to get a good bite and with CA glue it can actually interfere with the curing process.

I've stopped sanding tubes about 8 or 9 years ago, and my glue up failures (especially with back painted blanks) dropped significantly.

 

[PenMan1]

The coating is put on the tube for a purpose. It's there to stop oxidation and make the glue adhere better. Sanding the coating OFF promotes oxidation and contaminates the glued area.

 

[PenMan1]

With aluminum (such as segments) it is absolutely essential to sand the metal parts. The coating on many types of aluminum is to keep food and beverages from picking up the taste of the aluminum.

Other than JB Weld, I've never found a glue that will adhere to coated aluminum. Same for brass door shims. The have a "varnish" that makes them shiney.

 

[WriteON]

You broke the code. I do the same thing. I gently skim the tubes with 60g.
It fast. Less wear and tear on the hands/fingers. Works for me.

 

[Rodnall]

I thought the coating was to prevent oxidation but would cause problems with adhesion.

 

[edstreet]

The best surface prep for glue/epoxy is bead blasting. The second best is sanding. This is assuming that all surfaces are cleaned as they should be. This has been proven time and time again via performance testing.

 

[cal91666]

This is a very interesting topic. Every video and tutorial I've seen or read said to sand/scuff the tubes. I always clean the tube after sanding/scuffing with DNA. Following this discussion.

 

[glenspens]

some of the last kits I got the tubes were sand/scuff when I got them

 

[PenMan1]

I think Ed hit the nail on the head. A clean surface(s) is a must to achieve a permenent glue up.

And I think it would be an interesting poll to see who sands, who blasts and who cleans with Acetone, Accelerator, DNA, etc.

 

[its_virgil]

I agree with Andy. I stopped sanding tubes for gluing years ago also. Clean them but no sanding. Ever tried to glue something to a dusty surface? Brass dust is dust and will interfere with the bond. I have no problems doing it this way. Many of the little things we do tend to be overkill.

Why do we sand tubes, someone ask? Years ago when the first pen kit was sold I'll bet the salesman told the customer he had better sand the tubes for good glue adhesion. They sell sandpaper! I took a pen turning class at Woodcraft after I decided to start this journey. I came home with a finishing regiment that included 7 products not counting the various grits of sandpaper. They sell those products and push them in their classes. I do not use any of those 7 products any more and haven't since about pen #5. Just my take on the subject.
Do a good turn daily!
Don

 

[sschering]

If the kit didn't come pre sanded I will run the tubes between centers and sand with 120.
Post sanding I'll wipe them down with a little Windex.. No special reason for Windex other than I keep a bottle hanging on the peg board for wet sanding so it's there and handy to use.

 

[Rangertrek]

I guess I will add my 2 cents worth to this discussion. I do a quick sanding on the tubes. I hold the tube on an insertion tool and scuff it on one of those foam sanding pads (HF), wipe it off and go. On the new tubes, I wipe off and glue. I also only use Gorilla glue and have had 2 failures in past 3+ years. I think one of the failures was more my fault than the glue.