Sanding mandrel VS Finish size mandrel

O

olsonsview

AzB Silver Member
Silver Member
I was recently asked how many thousanths difference in diameter should they use between the initial sanding mandrel, and a second final sanding mandrel to use after the finish is applied to get to final joint sizing. They wanted to make their own mandrels. I never really compared finishes and thicknesses. I have used as little as 4 thousandths difference for thin superglue finishes.
Anyone care to share the size difference they prefer with various finishes? Can we stick to diameters rather than radius to keep it less confusing? I hope this gets interesting, thanks in advance for any comments. A quick description of how many coats of whatever, and even brands may be helpful to many.

Superglue

Auto clearcoat

Epoxy base with water based clear

Epoxy only

Plus any other permutations anyone wishes to throw out there. There is no wrong answer here guys. Just cool information exchanges.
 
Mine are .828" and .840" so my finish ends up .006". I mostly use an epoxy finish that takes three coats. If I ever need a touch up or repair I can quickly build it up with CA.

Eric
 
josie said:
Mine are .828" and .840" so my finish ends up .006". I mostly use an epoxy finish that takes three coats. If I ever need a touch up or repair I can quickly build it up with CA.

Eric
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That is pretty thick.
.012" ?
 
I only use the finish arbors. They are .855". My final cut is .848". I never seen the point of using a sanding set as I can dial in the final cut pretty much on the nuts every time. The only other issue I could see that sanding arbors would 'correct' would be if you aren't getting the joint pin centered. The arbors would allow you to sand the cue center to the pin. But if your pins go in straight & center and you have good control of your final cut, then the sanding arbors unnecessary, IMO.

I screw the arbors on before applying the finish, then cut/sand/polish the finish once cured flush to the arbor. That ensures I never get finish on the joint face or get excess finish build-up at the joint face edge. It's only a few thou thick on each side. I have tried thicker finishes but that's where I begin running into issues like finish lift at the facing edges & such. Arbors can be a very important tool, but still requires a learning curve to get right. I'm still getting better with mine & have had them a few years now.
 
JoeyInCali said:
That is pretty thick.
.012" ?
Click to expand...

I measured mine again and they are .830" and .840" for .005" per side. Is that too thick? I have had issues of the finish lifting before but not all the time. I did not think of the thickness of the finish causing it. Could .002" or .003" make a difference?
 
qbilder said:
I only use the finish arbors. They are .855". My final cut is .848". I never seen the point of using a sanding set as I can dial in the final cut pretty much on the nuts every time. The only other issue I could see that sanding arbors would 'correct' would be if you aren't getting the joint pin centered. The arbors would allow you to sand the cue center to the pin. But if your pins go in straight & center and you have good control of your final cut, then the sanding arbors unnecessary, IMO.

I screw the arbors on before applying the finish, then cut/sand/polish the finish once cured flush to the arbor. That ensures I never get finish on the joint face or get excess finish build-up at the joint face edge. It's only a few thou thick on each side. I have tried thicker finishes but that's where I begin running into issues like finish lift at the facing edges & such. Arbors can be a very important tool, but still requires a learning curve to get right. I'm still getting better with mine & have had them a few years now.
Click to expand...
You finish right over the arbors? Do you have problems breaking the arbors loose once your finish has cured. I realize once you sand flush the arbors should just spin off but I would think you could run into troubles like lifting and chipping the finish when breaking them loose.

Thanks for the help.

Eric
 
qbilder said:
I only use the finish arbors. They are .855". My final cut is .848". I never seen the point of using a sanding set as I can dial in the final cut pretty much on the nuts every time. The only other issue I could see that sanding arbors would 'correct' would be if you aren't getting the joint pin centered. The arbors would allow you to sand the cue center to the pin. But if your pins go in straight & center and you have good control of your final cut, then the sanding arbors unnecessary, IMO.

I screw the arbors on before applying the finish, then cut/sand/polish the finish once cured flush to the arbor. That ensures I never get finish on the joint face or get excess finish build-up at the joint face edge. It's only a few thou thick on each side. I have tried thicker finishes but that's where I begin running into issues like finish lift at the facing edges & such. Arbors can be a very important tool, but still requires a learning curve to get right. I'm still getting better with mine & have had them a few years now.
Click to expand...

Please correct me if I am wrong. Is not a finish arbor just a different word for a sanding mandrel? If that is true then your process is little different than the rest of us who use sanding mandrels. The main difference is that what you said makes all of us who use sanding mandrels look like a bunch of idiots.
 
josie said:
I measured mine again and they are .830" and .840" for .005" per side. Is that too thick? I have had issues of the finish lifting before but not all the time. I did not think of the thickness of the finish causing it. Could .002" or .003" make a difference?
Click to expand...

Kinda thick.
I have one at .855 and I only use it BEFORE finish is applied.
I keep the butt and shafts at .857-.858 then I sand them.
The butt mandrel has an angle. The shaft does not.
You can tell when someone sands where they mate flat and then it causes a divot when he doesn't sand with the angle of the collar.
 
Hi,

I got my sanding mandrels from John Rocker and here is my modified procedure since I now use his mandrels - for what it is worth.

Cue's final dimension = .837

Sanding Sealer applied and flat sanded smooth with 110 psi air.

Wipe with denatured alcohol.

3 coats of G5 epoxy applied every 3 to 4 minutes @ 80 degrees for a monolithic substrate base for the clear coat.

Wait over night and sand cue flat to .841 -.842.

Wipe with automotive safe lacquer thinner.

Tack cloth and spray 4 coats PPG Auto clear which gets me to .855 to .857 @ 80 degrees.

Let units cure 7 days or more which lets the finish shrink down.

Step wet sand with .850 mandrel in place between centers.

Buff out.


By adding more epoxy than I need, I am able to flat sand my cues to a number without any worry about burning through. After spraying I wait 7 days and don't get the shrinkage after wet sanding to the mandrel. That .850 holds up.

I used to wet sand and buff after 2 days and experienced some dimensional shrinkage. Since I got my mandrels I now have a concentric datum relative to the shrinkage factor of the clear that has a physical comparison yardstick ie. - the precision mandrel.

Now that I am waiting the extra 5 days I have found that I don't have the very tiny swirl marks to deal with in the buffing as the clear is so much harder during wet sanding and the swirl marks can't get as deep into the harder finish. Adding a mandrel to my procedure made me aware of how much shrinkage does take place over time. Waiting the extra days was a nice collateral element that has made my buffing process go much faster as I am not trying to go deep with a lower grit compound.

Rick G
 
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Arnot Wadsworth said:
Please correct me if I am wrong. Is not a finish arbor just a different word for a sanding mandrel? If that is true then your process is little different than the rest of us who use sanding mandrels. The main difference is that what you said makes all of us who use sanding mandrels look like a bunch of idiots.
Click to expand...

You are right, just differing terminology. My post is referencing the idea of using two sets. Some guys use a set to sand the cue to after final cut before finish, then another set to sand the finish to. I use only one set, which is the finish set. And my post wasn't to make anybody look like idiots. Just pointing out that I have no use for pre-finish arbors because i'm careful to machine everything accurately to begin with. And if a guy pays attention to machine things accurately, then there's not much use for pre-finish arbors. Finish arbors on the other hand are something I wish I had bought in the very beginning because they are almost as important to me as the lathe. Hope that makes more sense. Didn't mean to confuse anything.
 
josie said:
You finish right over the arbors? Do you have problems breaking the arbors loose once your finish has cured. I realize once you sand flush the arbors should just spin off but I would think you could run into troubles like lifting and chipping the finish when breaking them loose.

Thanks for the help.

Eric
Click to expand...

Yes I finish right over the arbors. If your joint faces are clean & smooth and the arbors fits clean against it, no finish will get in between them. I cut/sand the finish until it's gone from the arbor, then polish & unscrew the arbor. It doesn't break or chip the finish from the cue. It only does so if you never got it all off the arbor, in which case it wouldn't be a flush fit to the other components anyway. If you get it clean & smooth & flush with no finish left on the arbor, it'll never chip as you take it off. Try it on scrap & you'll see what I mean.

Once the arbor comes off, I lightly sand the edge of the finish with 600grit between centers to just barely take the sharpness off the edge. That prevents it from grabbing & lifting as you put the cue in & out of the case. What you end up with, if you did everything correctly, is a finish where the shaft fits so smooth & flush to the butt that you can barely feel it, if at all. The only downside to the technique is having the arbor tied up on one component from beginning to end of finish, so you can only do one component at a time. My finish is quick so it doesn't matter much to me. But if I were still spraying auto clear or slow set epoxy, it would be annoying as I could only do one shaft at a time. The plus side, besides being so clean fit, is that I can make a thousand shafts for one butt & they all fit perfect flush. I don't screw the shafts on to the butt until the cue is finished and I know every single time that it'll be a dead nuts fit.
 
qbilder said:
You are right, just differing terminology. My post is referencing the idea of using two sets. Some guys use a set to sand the cue to after final cut before finish, then another set to sand the finish to. I use only one set, which is the finish set. And my post wasn't to make anybody look like idiots. Just pointing out that I have no use for pre-finish arbors because i'm careful to machine everything accurately to begin with. And if a guy pays attention to machine things accurately, then there's not much use for pre-finish arbors. Finish arbors on the other hand are something I wish I had bought in the very beginning because they are almost as important to me as the lathe. Hope that makes more sense. Didn't mean to confuse anything.
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I make sure everything is centered also. I still like to sand my cues to size before I start spraying so that I know exactly how much finish to apply -- not just build it up and up and up and then size it accurately on a finish mandrel. I am accurate all the way along.

As long as the cue's butt and shaft are the same size and there is a smooth transition between the two then it don't matter one little bit how you get there.
 
Arnot Wadsworth said:
I make sure everything is centered also. I still like to sand my cues to size before I start spraying so that I know exactly how much finish to apply -- not just build it up and up and up and then size it accurately on a finish mandrel. I am accurate all the way along.

As long as the cue's butt and shaft are the same size and there is a smooth transition between the two then it don't matter one little bit how you get there.
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I don't sand much after my final cut. I hit lightly with 400 for a few seconds & that's it. It doesn't really remove anything measurable, just roughs up the smooth cut surface for finish penetration. Tomatoes potatoes
 
What qbilder said.... if you can get to where you use a quick shot with some 400, and be good to go, it makes the finishing go very smoothly.
Sanding is imprecise.
I don't care how good you think you are with a piece of sandpaper, I'm going to cut more accurately with a tapering machine.
Sure, you can get close enough to nice and flat with sanding, but in my mind, it's better not to have to go there.
Sanding can also be problematic when you have materials of different hardnesses, or materials that are very light colored and/or porous.
 
some good points have been raised so far

And Yes, it is good to strive for a near perfect finish from tapering with little sanding required. BUT most makers in early stages will be lucky to make two cues the same joint size in a row, let alone have the skill to maintain a fixed size over any period of time without the use of some type of mandrel. I am sure there are many new makers that are grateful for the knowledge shared in this thread, and the many informative internet discussions that have evolved here on AZ.
Please continue guys, anyone else have anything to share or add?
 
olsonsview said:
And Yes, it is good to strive for a near perfect finish from tapering with little sanding required. BUT most makers in early stages will be lucky to make two cues the same joint size in a row, let alone have the skill to maintain a fixed size over any period of time without the use of some type of mandrel. I am sure there are many new makers that are grateful for the knowledge shared in this thread, and the many informative internet discussions that have evolved here on AZ.
Please continue guys, anyone else have anything to share or add?
Click to expand...

I resemble that remark!! :thumbup2:

Gary
 
A quick summary

So very interesting spread of finish thicknesses and techniques used to reach them. It seems certain that one thing any aspiring cuemaker should do is find a finish technique and size he likes, then work at making his skills and machine setup accurate enough to hold tolerance.
I would like to quickly run down what has been posted so far:

maker Sand dia. Finish Dia. finish used thickness

Josie 0.830 in 0.840in Epoxy-3coats 0.005

QBilder 0.848in 0.855in 0.0035in
(no mandrel to sand)

JoeyInCali 0.855in no mandrel

scdiveteam 0.837in 0.850 Epoxy+autoclr 0.0035
(no sand mandrel)

ChrisByrne base dia mand base+ 0.007mand 0.0035

Olsonsview 0.837 0.840 superglue 0.0015

Some interesting stuff. And guys, please correct me if I made an error, or left out something.


I no longer use the Superglue, have not for the past 18 months. All this discussion has made me think I should sell one set. SO I find myself with a set of mandrels I may sell: 3/8 X 10 thread with carbide sleeves of 5/8 id and 0.840 od 1 butt mandrel, two shaft mandrels. I had them machined for me. PM me if interested. And no lowballs please, they are hardly used! Sold only as a set of three. The reason I had them made that size is so I can use the unique aluminum arbors (5/8 od) easily when I needed to do an odd sized thread. The carbide is a light press fit to the arbor.
 
In the mid 90's I had my original carbide sanding mandrels made in two sizes, .845" and .850". I used the .845' to sand the cue to before finishing. That worked pretty nice with the auto clear coat with .0025" thick finish. But a few years later when I switched to the Cue Cote epoxy finish I found myself sanding through the finish too often. So I quit using the .845" and just use the .850" and cut my cues to .840" to .842" and sand smooth. My goal is .005" depth of finish. As a brush on finish is harder to control thickness it worked out better for me to put the finish on thicker and sand to the mandrels. I seriously doubt I will go back to the auto clear coats as they seem to be much more toxic. I hook up a gear motor on a five hour timer to my lathe and apply the finish, pop the bubbles with a torch and call it a night. It is the last thing I do before closing shop. I don't have to worry about dust getting stired up, or a customer touching the cue while it is still drying saying, "Wow that cue sure is shiney." Yes it happened! :)
 
olsonsview said:
All this discussion has made me think I should sell one set. SO I find myself with a set of mandrels I may sell: 3/8 X 10 thread with carbide sleeves of 5/8 id and 0.840 od 1 butt mandrel, two shaft mandrels. I had them machined for me. PM me if interested. And no lowballs please, they are hardly used! Sold only as a set of three. The reason I had them made that size is so I can use the unique aluminum arbors (5/8 od) easily when I needed to do an odd sized thread. The carbide is a light press fit to the arbor.
Click to expand...


Why not keep them? They are paid for & could come in handy later.
 
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