Pipe clamp pipes: galvanized or black or zinc?

[Pete Rowley]

Since I shall shortly be on the receiving end of some pipe clamps (http://http://www.sawmillcreek.org/showthread.php?t=42558) I figured it might be a good time to find out what folk think about the various types of pipe that can be used. I see black pipe stains wood, galvanized pipe can slip, and zinc is very shiny. So, what do y'all do to clean up your black pipe, unslippify your galvanized pipe, and er, what about zinc from rockler, any other sources?

[Mike Henderson]

I've used galvanized pipe on pipe clamps for years and never had them slip yet. I think I'd bend the pipe before the clamps slipped.

Mike

[Steve Clardy]

I have both black [mostly] and galv.
Either will work.

[Rick Levine]

Black pipe is cheaper and from what I've been told is recommended. All of mine are black. It is probably unlikely that the galvanized coating will cause the clamp to slip but why take a chance when you can pay less?

[Mike Null]

I believe galvanized and zinc are the same. I stopped using black because they're too messy and even painted them with good results.

[Jake Helmboldt]

I use a strip of masking tape along the black pipe to prevent staining.

[Bart Leetch]

Dad & I have been using galvanized for a combined 80 years & its still going strong no problems. No black stains like I get from black pipe of which I have I think 6. NO black pipe for me ever again.

[Don Henthorn Smithville, TX]

because I HAVE had galvaized pipe slip at critical times. I think we fail to realize that pipe outer dimensions are not uniform. Some 3/4 inch galvanized will be larger than others. Probably depends some on the pipe and some on the thickness of the galanize. Too small a pipe and it will slip at the worst times. Even Black pipe will vary in size inside as well as outside. I followed Al Crandal's instructions in building a hollowing rig using black pipe. The instructions called for using a 5/8" bolt screwed into a 3/4" black pipe. That is the way he did it and it worked fine, but the pipe I had was larger on the inside and the bolt would go right into the pipe with no threads catching. Had to make a design change for that part of the project. For me, I will stick with black pipe. If galvanize works for you, be my guest.

[Rick Gibson]

I have only used black pipe but I put a strip of green painters tape or masking tape on the pipe. Works fine and cheaper than galvanized.

[glenn bradley]

Galv has never slipped for me and leaves no stains. A few cents more per foot and no worries.

[Charlie Plesums]

I thought pipe clamps were supposed to be used with pipe pulled out of old buildings, with rust in the center. People buy new pipes for pipe clamps???

[Bart Leetch]

I would like to find some used pipe like I did in the past
17' for $2.

[Larry Prince]

I've found that galvanized or black work equally well and havent ever had any problem with the black staining.

However, a better choice is heavy duty aluminum conduit. I don't know how the price compares to iron pipe but I do know that its MUCH lighter and makes clamp handling a lot easier. It'll give you a whole new respect for your Jorgys.

I'm sure that conduit could be bent with enough clamping pressure, but if you get to that point its too much anyway.

This is not the stuff carried at Home Depot. You'll have to find an electrical supplier. Well worth the search tho.

[Norman Hitt]

Like Don, I HAVE had clamps slip using Galvanized, (several times before I figured out what was causing it). I first thought it was bad clamp heads, so to test them, I put them on black pipe, and they didn't slip. I just don't trust galvanized anymore, so I usually put masking tape or a plastic bag between the black pipe and the wood, (when I use pipe clamps anymore, which is not very often).

I would like to know if anyone has used those shiny Zinc ones that Rockler has though.

[Barry Richardson]

I work in a shop that has both, Ive noticed the galvnized pipe slipping on several occasions, Now I always reach for the black pipe. My theory is the black pipe is softer and the clamp gets a better bite on it.

[Rick Christopherson]

Galvanize pipe will slip when it is new becuase the finish is hard and slick. It does not slip after the pipes have been used a while and the clutch plates from the clamps have scored the pipes. I've used both, but the only ones I have now are galvanized because I don't like the mess of the black all over my wood and hands.

Any pipe will slip if the clutch plates are installed backward. If you look at the plates, you will see that they have a sharp edge and a rounded edge. This is from the stamping process that made the plates. Make sure the sharp edge is engaging into the pipe, not the rounded edge. Another cause for clamps slipping is the loading spring may be weak. This could be why some people have more problems with slipping than others. You need to pre-load the clutch plates in order for them to grab the pipe, and if the spring is too weak, it will not grab.

When using new galvanized pipe, or any pipe that slips, simply apply a little pressure to the clutch plates with your thumb (in the same direction as the spring pressure) as you begin to tighten the clamp. Once the plates have started to engage they will not slip further.

[Don Henthorn Smithville, TX]

You may be right, Rick, but the pipes that slipped for me had been used for thirty years. I have never had black pipe slip. I think the thing is that pipe does vary in its material and construction. You never can be sure where and how the pipe you buy was made. Some galvanized work others don't.

[Rick Christopherson]

If your pipes had been in use for 30 years and they still slipped, it sounds like you were looking for an excuse for them to slip, otherwise you would have stopped using them 30 years ago. Pardon such a silly question, but if your clamps were slipping for 30 years, why would you continue to use them?

In response to all;
What I don't like about this discussion is that people make it sound like a galvanized pipe will "suddenly slip" in the middle of a glue-up after the clamp has been tightened. This is not correct. Once the clutch disks have engaged onto the pipe, they don't slip, regardless of the type of pipe. The only time they slip is before the disks engage, and therefore fail to engage.

If your clamps slip in the middle of clamping, it is most likely that Norm Abram has convinced you that you should barely clamp the piece, and this will result in the clutch plates from not fully engaging. If you follow this pilosophy, then you should be using different clamps.

[Norman Hitt]

If your pipes had been in use for 30 years and they still slipped, it sounds like you were looking for an excuse for them to slip, otherwise you would have stopped using them 30 years ago. Pardon such a silly question, but if your clamps were slipping for 30 years, why would you continue to use them?

Rick, did you stop to think that they might not have slipped before, but did finally slip? (That is definitely what mine did.

In response to all;
What I don't like about this discussion is that people make it sound like a galvanized pipe will "suddenly slip" in the middle of a glue-up after the clamp has been tightened. This is not correct. Once the clutch disks have engaged onto the pipe, they don't slip, regardless of the type of pipe. The only time they slip is before the disks engage, and therefore fail to engage.

I'm Sorry Sir, and not trying to pick a fight, but my clamps were VERY tight when I laid them aside to dry, and they DID slip later, much to my chagrin, because I didn't go back and check a few minutes later before I left the shop. (and NO, all the clamps didn't slip).

If your clamps slip in the middle of clamping, it is most likely that Norm Abram has convinced you that you should barely clamp the piece, and this will result in the clutch plates from not fully engaging. If you follow this pilosophy, then you should be using different clamps.

No, I do NOT subscribe to Norm's method of barely clamping either.

As I said before, If galvanized works for you, then use it, but for me, I just don't trust it anymore.

[Jim Hinze]

I too have had the galvanized pipe slip.. and it seems to be limited to one or two clamps which I will replace with black pipe.

I do like the convience of the galvanized pipe, especially working with woods that have high tannin content (e.g. Oak), the black pipe if in contact w/the wood will leave black marks on the wood... this can be avoided by using wax paper or plastic wrap inbetween the pipe and wood... but heck, I'm lazy sometimes :D

Never used the chrome/zinc pipe from Rockler... always seemed way too expensive for the benefit...

[Pete Rowley]

This is great stuff, keep it coming.

The heavy duty aluminium conduit sounds interesting, does anyone have an opinion on its strength?

It does seem like we have two camps regarding black vs galvanized (which was not unexpected), but this is all great information that I and others can use to make a decision. All the tips n tricks on dealing with the downside of whatever choice are exactly what I was after. Thanks!

[tod evans]

pete, use steel! but other than that, to me a pipe`s only a pipe. you`re going to sand/plane or otherwise finish the wood after glue up so just use whatever`s handy...02 tod

[Steve Clardy]

This is great stuff, keep it coming.

The heavy duty aluminium conduit sounds interesting, does anyone have an opinion on its strength?

It does seem like we have two camps regarding black vs galvanized (which was not unexpected), but this is all great information that I and others can use to make a decision. All the tips n tricks on dealing with the downside of whatever choice are exactly what I was after. Thanks!

I ran across some aluminum pipe several years ago in a dumpster.
[Yes I'm a part time dumpster diver:) ]

1/2"x 12, threaded on one end. I thought these would make great, short pipe clamps.
Well, the multi-spring pipe clamps, dig into the alum. so bad, that I have to use a mallet to get them loose.:mad:

I haven't throwed the alum. pipe away yet, but removed the clamp heads from them.

[Ben Grunow]

I bought a bunch of galv pipe for clamps at the borg and the darn things were too thick in some spots to fit through the clamp heads. Whatever ever chinese plant made them has bad machines because they were almost 1/8" larger than they were supposed to be in some places. Most aggravating thing ever. Black pipe with paint.