Glue-up question for lathe work

No, that will just get you diagonal stripes. For approximation of a helix (3-D spiral), glue up some striped strips, saw into squares, and glue up the squares with each one rotated a bit from the one below. For the shape you describe, you might want to use smaller/thinner strips on the part that will be turned smaller.

This type of common wind-dangly-thing should give the idea - you have to envision each strip of this being expanded to a full striped layer.

> > > > --

Thanks Ecnerwal, That explains it. I will do as you suggest.

Ivan Vegvary

I did that with some oak and purple heart - turned a handle for a big file. Big handle big file. It looks great, handles great and is slanted slices.

Martin

Mart> Wishing to turn a gear shift knob for my 1948 Pontiac. Automatic

1. I have a pile of squares of diamondwood that are predrilled to make shift knobs - these are probably not right for you (think near spherical shift knobs like on my 38 Plymouth or 36 Cadillac) but if anyone else would like one or more, drop me a note - not free, but not too dear (get my email from my web page at
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1. I think to make a truly spiral pattern I would not do it via glue up - for several reasons, one is that it won't look right, but an even better reason is that a car is a really really tough environment on wood and it is very likely to come apart. So, here are some other ideas

2. you can turn aluminum like wood, so make the shape out of aluminum (turn a little slower than wood), polish it, and then use "standard techniques" to cut a spiral groove into the AL and press a strip of wood into the groove - glue it in with epoxy

1. you can still buy bakelite if you wanted an original handle - it turns like a really hard brittle wood - dust, not shavings, but it can be turned on a wood lathe (as can FRP and Phenolic and nylon)

2. do as in #1, but make the handle out of one piece of hard maple, then do the grooving.

1. cut a maple dowel so it is 3/8 at one end, 1" at the other end. Steam

1/4 inch square strips (e.g. 1/4 X 1/4 X 24 inches) of your selected woods for a while, until they are soft and wrap them around the shaped dowel and glue in place - use clamps to hold the whole thing tight while the glue hardens - you can make a shallow spiral or a really twisty one like threads, your choice - the shallow spiral will be easier and use shorter strips of wood-

1. use veneer laid onto the shaped dowel

2. for something completely different, make up a shaped dowel exactly as you want the outside and use that to make a mold using silicone mold compound - then fill the mold with interesting stuff like bugs, or flowers, or chips of wood and broken screws and then pour in casting resin - after it hardens, polish on the lathe and drill/tap as required.

Hi Bill, I always read you posts in the rec.crafts.metalworking group.

Now you have me confused. All of your ideas are great! Don't know which one to choose. BTW, many years ago I did do a glue-up knob and it lasted only a few hours before splitting. At the time, I blamed on on the threaded hole, thinking maybe I stressed the part. Obviously, glue-up is not the strongest way to go.

Thanks again,

Ivan Vegvary

"Ivan Vegvary" wrote: (clip) All of your ideas are great! Don't know which

^^^^^^^^^^^^^^^^^ Since you are dealing with a classic car restoration, I would save all of Bill N's ideas for something else, and make a knob that duplicates the original.

On Wed, 19 May 2010 13:52:27 -0500, Ivan Vegvary wrote (in message ):

I will risk telling you something you may already know, in the belief that maybe someone else might pick up a little nugget on gluing. It is not my intention to cause anyone any insult.

The glued surfaces need a little truing up with a pass on a good flat sander

- but not too smooth. A "virgin" surface straight from the lumberyard planer may look nice, but it may be *too* smooth, it may have a very slight surface wax or other "protective" coating, or it may just have some schmutz that will interfere with the glue.

for the white or yellow woodworking glue... The glue needs to sorta soak in for a minute or two before clamping, as the naked surface will tend to absorb some of the moisture in the glue. If the work is clamped immediately after applying the glue, the wood will absorb some of the moisture anyway, and the joint will be starved.

When the work is clamped, expect some squeeze-out, but don't deliberately keep on tightening the clamps too much and squeeze out all the glue. The joint will be starved. Leave the squeeze-out alone. Clean it off after the glue has set up.

If using Gorilla (tm) glue or one of its cheaper (but equally good) clones, the gluing action depends upon a bit of moisture in the work, to activate the chemistry of the glue. A quick pass with a damp sponge on the candidate glued surface is useful. Do not clamp this job too severely, or the joint will be starved. The glue will foam a bit as it goes to work - just let it go and dry. Clean it off after it has set.

Epoxies are excellent, but again the wood has to be very clean and dry, and lightly sanded to insure removal of the oxidized and too-slick surface. The epoxy has to be throughly mixed for a minimum of a minute and two minutes is better. Clamp securely, but again, do not starve the joint.

Respectfully submitted, tom koehler

leo - I restore cars, as you know from my web page, but clearly Ivan is looking for a "custom" look rather than a "new from the factory" look. We all know that reproductions of many of these handles are widely available (of course for MY pink Cadillac, almost nothing in that color is available, but then again, what would you expect....).

Also, as something of a restoration purist - putting on an incorrect gear shift knob is harmless, you can always remove it and put a stock knob back on - on the other hand, taking a nice condition cream puff and doing a chop/channel job turns a collector car into a custom rod with no path of return. So, my bias is, customize the unrestorable and restore the good ones.

^^^^^^^^^^^^^^^^^^^^^^^^^ Bill. I fully understand and agree with your "bias." However, my suggestion was based on the OP's original question, which seemed to indicate that he was hoping for a simple way of producing an attractive spiral patterned knob, i.e., layering and turning on the bias. Since that isn't going to work, it seems to me that a knob turned out of a single piece would solve the problem most directly. A knob turned out of wood with an attractive grain would add a little sparkle without being "over the top."

How about a bunch of small white and black cubes to form a checkered flag pattern?