Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: Landlocked on May 20, 2018, 10:23:46 pm

Title: Clamping tubing?
Post by: Landlocked on May 20, 2018, 10:23:46 pm
Hi,


Does any have a trick or tool that allows me to clamp tubing in place while cutting threads on the end without crushing the tubing?


Seems like anything that holds it firmly in place also crushes it.  I've tried rubber vise jaws to no avail.


Inserting a thickwall tubing inside of the one being threaded is passable but I still get some crush and/or vise marks.


Could the flaring tools for brakelines work?  Do they come small enough?  I max out with 1/4 in tubing.


Ken/Landlocked
Title: Re: Clamping tubing?
Post by: tigertiger on May 21, 2018, 04:04:26 am
I am sure there are many ways to do this, below is what I would do. I already have tube benders, but you don't need them.
Title: Re: Clamping tubing?
Post by: ooyah/2 on May 21, 2018, 11:25:48 pm
Hi,


Does any have a trick or tool that allows me to clamp tubing in place while cutting threads on the end without crushing the tubing?


Seems like anything that holds it firmly in place also crushes it.  I've tried rubber vise jaws to no avail.


Inserting a thickwall tubing inside of the one being threaded is passable but I still get some crush and/or vise marks.


Could the flaring tools for brakelines work?  Do they come small enough?  I max out with 1/4 in tubing.


Ken/Landlocked



]Hi Ken,
You don't say what dia of copper tube you are trying to hold and then thread. remember that copper pipe in new condition is annealed so it will intend to collapse under pressure and when threading it the root dia of the thread is usually so thin to the inside wall it makes it hard to thread.

Do you need to thread copper pipe, can't you make bolt together flanges ?


George
Title: Re: Clamping tubing?
Post by: Landlocked on May 22, 2018, 04:10:22 am
Fuys,


Thanks for the suggestions.  I have to go find my bending springs.  Never liked them.  Seemed like I had to unscrew them off the tube once the bend was made.


Ken
Title: Re: Clamping tubing?
Post by: tghsmith on May 22, 2018, 10:35:54 am
I have used an adjustable type flaring clamp tool that will crank down to almost zero.. but it can leave tool marks.. another option for clamping shafts and tubes is an ER16 collet and holder.. I had a holder modded to fit my lathe, but mounted in a vise they would work very well as a clamp,,
Title: Re: Clamping tubing?
Post by: southsteyne2 on May 22, 2018, 11:19:43 pm
I use the little nylon wheels off sliding door runners ,works well for 1/8th to 5/32 tubeCheersJohn
Title: Re: Clamping tubing?
Post by: steamboatmodel on May 23, 2018, 01:33:11 am

I never thread copper tubing, always solder fittings on.
Gerald.
Title: Re: Clamping tubing?
Post by: Landlocked on May 23, 2018, 03:48:58 am
All,


Thanks for all  the suggestions.  I was able to get things to work this time.  I backed off to break the chips every half turn so I didn’t put as much torque on it so I didn’t have to clamp too hard. Good technique works. :D


 Progress pics on my main thread soon.


Landlocked
Title: Re: Clamping tubing?
Post by: Brian60 on June 08, 2018, 11:11:00 am
Just seen this, another option would be solid copper rod of the correct diameter, cut the thread on the end and then drill out the centre - as long as the finished length of pipe required is not too long! Or as above but on a smaller diameter than your required pipe, then insert solid piece into end of pipe and solder into place.
Title: Re: Clamping tubing?
Post by: Landlocked on June 21, 2018, 12:54:05 am
Oops!  >>:-(


I tried to tighten things too much and sheared off one of the fittings 


I decided the smart thing to do was to order a nipple and some "pipe" with thicker walls.


I was able to extract the stub using a screw extractor and save the fitting.


Landlocked