Thread Chasing ?

[Dan Bevilacqua]

I like turning boxes. I am interested in attempting thread chasing, and I (at this point) intend to buy the Sorby chasers. My collection of woods that may be suitable for thread chasing are only 2" square for small boxes.

I was hoping that someone could tell me the minimum inside diameter of a box for internal threading with the Sorby internal thread chaser, before I leap into thread chasing?

 

[robo hippy]

Umm, well, I use the Baxter threading jig, and that video should be up soon. I don't like going bigger than 1 1/4 to 1 1/2 inch at the very most. The problem is with wood movement, and no matter how 'dry' your wood is, it will adjust to having bulk removed. Beyond the 1 1/2 inch diameter, wood movement can be a problem. More of a problem if you move or sell to some one who lives in a different environment from where the wood has 'adjusted to' and is comfortable. I rough turn all blanks and let them sit for 6 or more months. If I wanted to go wild and crazy, I could do it like Eric Lofstrom who does 2 or so inch diameter boxes, and rough turns them in stages several times over about 6 months. As small as mine are, I don't think I need that process.

Another thing to consider is the wood you will be using. Not all woods will take to hand cut threads. Box wood is great, but expensive. Lignum does work. Allan Batty said the only N. American wood other than box wood that will take hand threading is mountain mahogany, but you will never find that on the wood markets. Some can chase sugar maple. I have also heard that PVC pipe works well for learning the process.

This is a skill I do need to learn....

robo hippy

 

[rkriet]

The Sorby internal thread chaser is less than 3/4” wide, so it can easily work in a box that is 1.5” or even 1” in diameter in the inside. I believe the Wyoming Woodturner has a several videos in which he shows needle boxes with hand chase threads. These boxes are no more than an inch wide on the outside.

I have had good luck using African black wood as inserts for the threads. I cut slices of Blackwood that are about 1/4 inch thick and glue these into the lid and the body of the box. Then chase the threads. It takes a little more time, but the results make it worth the trouble.

I rough turn the boxes and let them sit for a few months. After I turn them to final dimensions, I glue in the inserts and then let the boxes sit for a week or so in order to allow for any additional movement that might come from releasing tension in the wood. I’ve had good luck with boxes up to 2.5 inches.

I would note that it’s easier to learn thread chasing by going with finer threads; but the finer the threads, the more inconvenient it is to unscrew the lid off the final product. I personally do not like boxes with 4-6 fine threads — it takes too many turns to get the top off. So, initially, I will often chase more threads than I need, and after I have adjusted the fit and the grain match, I remove some of the male threads until there are only two or three remaining. That makes for a more “user friendly” final product.

I’ve been using chasers that are 16tpi and 12tpi, but I think I may order the 10tpi for this same reason — less turns to remove the top.

 

[Richard Coers]

You need to make the thread chaser choice before calculating the turning diameters. Should be lots of information if you do a search. This subject comes up often.

 

[Michael Anderson]

Allan Batty said the only N. American wood other than box wood that will take hand threading is mountain mahogany,

Why do you think that is? I’ve never worked with Boxwood, but I imagine it is very fine-grained. I suspect this is why it turns and threads well. Seems like there would be plenty of North American woods that are suitable. Off the top of my head Sourwood, Hophornbeam, Holly, maybe Dogwood. That said I have zero thread-chasing experience. Could be way off base.

Edit: did some digging. Here is a good related thread elsewhere on the forum: https://www.aawforum.org/community/threads/thread-chasing-density-and-other-considerations.12524/

 

[odie]

I don't have any thread chasing experience either, but I know that @Emiliano Achaval has done quite a bit of it in the past.

-o-

 

[Dan Bevilacqua]

Thank you for the responses. I did go ahead and order the Sorby 16 tpi set.

 

[Vincent Vogel]

I've dabbled in hand chasing, 16tpi Sorby cutters. I have used cherry, hickory, hard maple so far, hard maple worked the best. Cindy Drozda has a thread chasing you tube on her site until February 15 and it's pretty good. Look up Kirk DeHeer and see if you can find his video it's also good.

 

[Michael Beswick]

I did a similar thing a few months back and started with Sorby Handchasers. African Blackwood, Box wood work well., as does Mopane Lacewood. Other species available in the UK less so. Using CA glue is often suggested but in my experience doesn't really stabilise the thread tips unless used in visible quantities. However the technique is one where unless you do it very regularly it's easy to forget and basically wreck the box. Being impatient I bought a threading jig (Hope) which works very well. I'd also agree that too many threads makes removing the lid a pain. As for minimum diameter, the handchasers are small ? 1/4" x 3/4" at the business end but it's more the "elipitical" action that determines the minimum size. I found I couldn't get on with the "brace".

 

[hockenbery]

Seems like there would be plenty of North American woods that are suitable

I’ve chased threads in holly and dogwood.

 

[rkriet]

As an old wag said, learning to hand chase threads is easy - just lock yourself in the shop with a boat load of boxwood and practice chasing threads until you have screwed yourself into the ground!

Actually, it’s not all that hard, once you get the hang of it. Kind of like riding a bicycle. I have found that it’s more difficult if you try too hard and your muscles are too tense. Once you have the general principles down, it helps to just relax and search for that rhythmic movement that will cut the threads successfully. Yes, if you’ve been away from it for a while, you’ll have to practice on a scrap piece of wood in order to refresh the muscle memory. But if you do it regularly, you’ll find that you can chase threads by hand faster than you can set up and use an expensive jig. Not to mention the fact that, at least for me, it much more satisfying to produce a good hand chased thread than to produce one with a jig. Maybe it’s just me, but I enjoy the challenge and the sense of accomplishment that comes with a successful hand chased thread.

By all means, if you’re interested in trying it, watch some YouTube videos first. In addition to the ones already mentioned, just search for “thread chasing” and you’ll find some excellent lessons. I learned a lot from an old video produced for Craft Supplies by Alan Batty. San Angelo and Mike Peace also have very helpful videos.

 

[Randy Brunzlick]

Unsolicited comment:
Mike Mahoney does great demonstrations on hand thread chasing.
Here is a link to one deomo

View: https://www.youtube.com/watch?v=FmfULB2ZdLg

If I recall correctly the higher the specific gravity of the wood the better it works for threading.

 

[Dean Center]

FWIW, PVC pipe fittings, like a coupler, can take chased threads. They're a whole lot more available and less expensive than boxwood or African blackwood to learn or refresh on.

 

[Randy Brunzlick]

FWIW, PVC pipe fittings, like a coupler, can take chased threads. They're a whole lot more available and less expensive than boxwood or African blackwood to learn or refresh on.

Reasonably priced for practice is good.

 

[robo hippy]

There are probably a lot of woods that can be used for hand chased threading. The problem is finding them. The thing with 16 tpi on your thread chaser means that you will not have to remove more than 1/16 inch of shoulder on the tenon to get the grain to line up. I do have a stash of box wood from when my house was built, so I will get around to it some day.

robo hippy

 

[john lucas]

I have chased threads in epoxy. I cut grooves in the woid. Fill with epoxy. Then turn away the wood and chase the treads. Skill plays a huge roll in whatvwiids work. Boxwood is the best I've used. Blackwood works well. Katalox works. Can't remember for sure but think I have done it with cocobolo. I've seen Nark StLeger chase threads in wood that I can't. Although I did thread some hard maple the other day. Could not do that years ago. One technique I've been playing with is pushing the tool every pass rather than letting the wood pull the tool. I need more experimentation but it seemed like I got cleaner threads in marginal wood.
Most of my threading is done with the Baxter threader. Wonderful machine. Most of the wood I use foe my boxes simply won't take hand chased threads.

 

[Dean Center]

I do have a stash of box wood from when my house was built, so I will get around to it some day.

Reed, this is a little off the subject, but why would you have boxwood leftovers from building a house?

 

[robo hippy]

There was a large, maybe 30 inch diameter western incense cedar, which is good only for pencils, right in the middle of where my house was going to be. Under it, there were 3 boxwood trees, the largest being almost 6 inch diameter. The tree and the boxwood came down, and now I have a big stash of boxwood. I had to take out a lot of trees on my property. The incense cedars, not what grows out in Tennessee, and grow to 80 or so feet tall were planted under power lines. I am replanting a much more diverse forest on my one acre.

robo hippy

 

[Michael Anderson]

That’s pretty fortunate about the Boxwood Reed! If you find yourself in need of offloading a little piece, feel free to send it my way.

 

[GRJensen]

Another option: Corian. I have chased threads in Corian, and used it for inserts in turned vessels. As I see it, the principle advantage of using Corian is it is not subject to wood movement. I got a box full of cut-offs from a guy that does kitchen counter-tops ... probably enough to last me a lifetime!

 

[robo hippy]

I do have some old sheet stock that is pretty much particle board, but made with dyed paper. I think it should work as well. Hadn't thought about the Corian. You could do some nice colored and segmented pieces with it. Oh no, now I am thinking pepper mills.....

robo hippy

 

[Jeff Jackson]

I've done close to 300 threaded boxes but I use the chefswarekits.com threading jig. Most of my boxes end up in the 2-1/2 to 2-3/4" range and it's usually not an issue with wood movement providing the piece is seasoned and stress free (even kiln dried stock get rough turned and allowed to season a few months). Also threading allows me to have a slight clearance in the threads just in case. For my 16tpi boxes, I use an offset of 3/64" (I learned from a Bonnie Klein handout) and it's always worked fine.

 

[Vincent Vogel]

I experimented with black locust today and it went ok, had to keep wax on it. Now I have to learn to match the male and female threads for size. My female thread went ok but had trouble with the male thread and the box I was trying to make ended up too short to use for anything.

 

[robo hippy]

I make the recess 3/8 inch deep. This allows room for adjusting the shoulder on the tenon down 1/16 and a little more if I go past that. The tenon I make 1/4 inch tall. Again, that shoulder gets adjusted down for the perfect fit/timing of the threads and grain. Vincent, your tenon and recess appear to be about the same size/length. You can trim the top of the tenon down if you run out of room.

robo hippy

 

[Richard Findley]

I like turning boxes. I am interested in attempting thread chasing, and I (at this point) intend to buy the Sorby chasers. My collection of woods that may be suitable for thread chasing are only 2" square for small boxes.

I was hoping that someone could tell me the minimum inside diameter of a box for internal threading with the Sorby internal thread chaser, before I leap into thread chasing?

I gave ground the back off of most of my internal chasers so they can fit in a tighter space. Easy to do, you just have to be patient as with any grinding operation.

HTH

Richard

 

[Vincent Vogel]

I make the recess 3/8 inch deep. This allows room for adjusting the shoulder on the tenon down 1/16 and a little more if I go past that. The tenon I make 1/4 inch tall. Again, that shoulder gets adjusted down for the perfect fit/timing of the threads and grain. Vincent, your tenon and recess appear to be about the same size/length. You can trim the top of the tenon down if you run out of room.

robo hippy

The top recess is 3/8", the bottom male thread is about 1/4" to 5/16" but I cut some off of it because it ended up too long from mistakes. Usually I have trouble with the female thread but this time the male thread gave me fits.

 

[robo hippy]

They do that some times.... Done that more than once.... The tenon and recess need to be spot on parallel, and not angled even a tiny bit. I use a 6 inch steel ruler to eyeball it against the lathe bed. I do need a small x/y cutter for making boxes....

robo hippy