Welding questions on a woodturning ng? (Iknow you guys better)

I don't know about the strength of JB Weld in this application, but you may have a problem with alignment if you are searching for perfection.

On the other hand, I DO know about welding galvanized steel. It can be done, and it's not all that hard. However, the galvanizing is zinc. Welding releases zinc fumes, and they are poisonous. If you must try it, use EXCELLENT fume exhaust and mask. Better yet, think again and don't!

Jim

Arch wrote:

Greetings,

Try asking this question in rec.crafts.metalworking. When you get an answer, please post it back here.

S> I want to make some Read type

sci.engr.joining.welding is a very nice newsgroup, Arch.

If you insist on welding, strip the zinc off first, or buy some non-galvanized parts. Zinc fumes are verrry bad news.

Whether welding or JB-Welding, your accuracy is probably going to suffer from welding. This adapter should be machined - then it would be accurate. It could be welded and then machined, but then you'd want to start with something bigger than the threads you'd like to have on the finished part. If you were stuck on a desert island with no recourse, etc...

JB Weld has its uses, but I don't think this is one of them.

Best bet, if I understand what you are trying to do, would be to get your discs re-threaded to fit your spindle nose. While some pro shops will charge an outrageous rate (precisely because they don't want the business) other shops and home shop folks (try rec.crafts.metalworking - a bit more traffic than I can currently wade through) will do a simple job like this for not much money, or a 6 pack of "beverage of choice". You could offer to thopw in a few wooden mallets for beating on fine metal things without dinging them up.

^^^^^^^^^^^^^^ It has been discussed estensively on rec.crafts.metalworking and on Sci.engr.joining.welding. Welding galvanized steel produces zinc oxide, which is recognized as being quite toxic. It used to be said that after welding galvanized, you should drink lots of milk, to counteract the "heartburn." I have welded lots of galvanized material, in my ignorance, and wasn't aware of any after effects. However, I don't do it any more without breathing protection.

The zinc oxide looks like wisps of cotton, floating in the air and clinging to the welded metal. It seems to me that a well placed fan, together with a simple particle filter should suffice, but I am not an authority on this, so please treat what I say as well intentioned, but unreliable.

re welding to galvanized steel - don't.

Unless the zinc (what you think as galvanizing) is removed the home /hobbiest welder will probably get zinc chills at a minimum, could wind up in a hospital at worst, plus the weld will most likely be very weak because of the zinc inclusions in the weld material.

For you that know weld> I want to make some Read type

Thanks all, for the good advice. I'll follow it. I had hoped that electrogalvanized bolts could be safely welded. L.S. I thought to avoid machining the adapter and just flat the glue blocks that I like to use, but your advice is preferable.

As an OT aside, early in WW2 mess kits & canteens were zinc coated. Those days 'GI gripes' referred to their gut, not to the soldier's usual gritching. :) Arch

Fortiter,

Late arrival, last evening my neighbor welded 12 (2 1/2' OD X 1/8" thk.) washers and 1"x 8 zinc plated nuts (commercial grade). After welding, the wobbling and out of round were found to be at a very minimum. The stress relieve was rudimental. After welding the face plates they were dropped on the concrete floor to cool off and plunge in a two gallons bucket of water. He used a basic commercial mild steel welding rods. The 35 years of shipbuilding welding experience of my neighbor accounts for the proper preliminary tacking and good heat distribution of the fillet weld. Only 10-15% of the zinc plating remained on the metal. A light buffing on the wire wheel cleaned the face plates well. I then deburred the holes with a carbide countersink tool. Unless done as per Military or Nuclear specs the quality of the zinc plating found is very minimum. I also found that drilling the holes on the washers before welding makes it easier. The next time, to have a better hole circle I will try grinding a 45 degrees bevel on the nuts before welding them. As stated before in the previous post, once the wood block is fastened and trued on the lathe the wobbling an out of round is very acceptable to me.

If you're truing up the wood block, then some slop in the adapter is fine. I didn't get that part from the original post. You can remove the galvanizing with muriatic acid, but I'd rather buy new hardware to weld up than frig around with muriactic acid, personally.

It seems ok to continue a discussion of metalworking on a woodturning ng because having several faceplates (I like the term 'multiscrew chuck') has many advantages over juggling one scroll chuck. I plan to drill & tap some 3 X 3/8 in. stressproof steel discs 1,1/4 X 8, and make a spacer/register sized to leave 1/4in of my N3K spindle exposed to attach the discs to. Any fallacy to doing this? For some reason the cattle and farming industries hereabouts use a lot of this size steel bar, so it is cheap and cutting it costs about a buck a slice. Unfortunately the prices of drills, taps & dies jump beyond 1 X 8 threads. :( , but compared to ready made, these homemade multiscrew chucks are a good value for tinkerers. Lawrence, I'll do it myself and share _my choice of beverage if you come to Fla. ;) Also, what about dinging up _my fine wooden mallets? ;) As for muriatic acid and zinc oxide..., anyone want to buy some galvanized bolts cheap? Arch

Fortiter,

Regarding the truing up of the new faceplate.

This can be easily done right on the lathe. Screw the faceplate on the headstock, run the lathe at a low speed and using piece of HSS either bought for the purpose or even a scraper or gouge. (This will ruin the edge somewhat but can be reground later). Place the tool rest very close and lightly draw the cutting tool across the face of the plate. It will take some time but light cuts and care will produce a perfectly true surface to suit your lathe assembly.

I have made several faceplates using a nut and a piece of scrap steel and trued them up as described. I also scribe several different circles on the face to assist placing a turned piece accurately on it. Also I like to make the plate slightly dished (concave) so that the item will sit on the outer circumference, this also leaves slightly more room for the hot melt glue which I use if the piece has a finished base.

Incidentally hot melt glue works really well with a steel faceplate because it can be preheated to ensure the glue does not chill on a cold plate and it can also be warmed up with an iron or hot air gun to remove the plate later.

Cheers from 'Down Under'

What do you call slow speed. Do you use cutting oil? Is there a cutting angle on the piece of HSS?

Hello Denis. The speed is not critical but I found that when it was too fast the cutting/rubbing produced a squeal as the disc highpoints touched the cutting tool. (In this case more like a scraping than a cutting action). Having a Vicmarc with variable speed control I just slowed it down until this stopped, but in any case my guess is that it was low 100's RPM. Once the disc became true and I was getting full contact, I increase the speed, resharpen the tool and take light shavings just like on timber. Because of the hardness of the steel compared to timber, the tool was ground to scraper angle i.e.. just slightly less than 90 degrees. I have made up several small scrapers and gouges for my woodturning, using HSS metal cutting toolbits from 1/4" 5/16" 3/8" square and round steel bar. I have found that the easiest tool to use is the 1/4" square scraper ground to a slight curve, probably because it takes the smallest cut. This produces a fairly good flat finish. For roughing down the disk I might use a pointier shape on the tool. Keeping in mind that I am hand holding the tool, it is easy to deflect it away if the cut is too deep. I have it in mind to set up one of the vices that can be moved in two directions (such as a cross slide on a metal working lathe). This would make it possible to face the plate quicker and more accurately. But at present that is not a high priority seeing that I am getting the work done anyhow. :-) Cheers, Peter.

"Denis Marier" wrote in message news:d9Ldb.17043$ snipped-for-privacy@ursa-nb00s0.nbnet.nb.ca...

Thanks Peter, I did a few of my face plates at 650 RPM. It worked good. It would have worked better at lower RPM. This is one requirement for my next lathe.