Advice needed!

[Ray Dunakin]

To make the gauge on the water tower I'm modeling, I need to cut a lengthwise slit in a 1/8" brass or aluminum tube 11 inches long. Unfortunately I'm at a loss as to how to do this, particularly since I only have hand tools. Any suggestions?

[toenailridgesl]

Ray,

I did a similar model job. I cut the 3mm tube down the middle using the bandsaw then super-glued it back together with a 1mm styrene strip separating one of the joins. If you need more strength you could use a steel spacer instead of styrene & solder the pieces together. The glued or soldered joint is to the back so it doesn't show anyway.

Using only hand tools is a challenge but considerable persistence with a sharp blade would eventually split one side of the tubing if you held it securely in a vice & used a straight-edge to keep your blade true.

Regardless, pix will be appreciated of the finished products, or of progress.

[Anonymous]

I did something similar on 15 mm tube - insert a wood dowel that is a reasonably tight fit inside , cut the slit with a cutting disc in a dremel , The dowel seems to stop the disc binding and breaking and makes for a cleaner cut . I found it took ages btw.................

[fontgeek]

Is this going to be a working guage, or strictly visual? If it is going to be working, what are you going to put inside of it to work as a sight glass or guage?
Why not go the cheaters route and use a fineline masking tape or pinstripers tape to mask off the desired viewable section of the guage, then paint the rest in the desired finish? Even if it is just a piece of clear, acrylic rod cut to length, it would still give you the desired look, with no sharp edges, and no seams, or lips to fight with.

If you trully want to cut the tubing, and you only want to use hand tools, I would do the dowel trick, and use a sharp boxcutter. Do multiple long passes over the entire length of the tube until you cut through. It may take several blades. The dowel keeps the vice from crushing the tubing, and it keeps you from cutting through both sides of the tubing if you get over zealous in your cutting.
Good luck!

[Ray Dunakin]

The way the prototype works is, there's a weight inside the tube, with a marker sticking out through the slot. The weight is attached to a cord that goes up to a pulley at the top, and down into the tank. At the other end of the cord is a weighted float. As the water level goes up or down, the marker goes up or down correspondingly.

What I ended up doing was cutting the slot with a cutting wheel on a Dremel. Very tricky, trying to keep it going in a straight line. It's not perfect but close enough to look good, especially after it was painted.

I finished the tower a couple weeks ago and will have pics online as soon as I get around to uploading them.

[Anonymous]

Glad it is going well Ray - will be interesting to see the end result.