CS 17 Masts Purchase

[Dale Niemann]

I just ordered my masts from http://www.onlinemetals.com/index.cfm. Here is what I ordered and the prices. The sizes were based on availability, UPS shipping cost and Bill Heil & Graham's recommendations. They indicated an overstock on 2.5" for what it is worth.

Qty Description - Size Price Total

2 Aluminum 6061-T6 Bare

Drawn Tube

2.25" x 0.065" x 2.12"

Cut to: 96"

$33.26 $66.52

2 Aluminum 6061-T6 Bare

Extruded Tube

2.5" x 0.125" x 2.25"

Cut to: 96"

$42.84 $85.68

Shipping Cost: $28.04

[Dale Niemann]

Graham or Bill Heil,

I purchased my masts in two 8ft sections of 2.5 X

0.125 and 2.25 X .065 as in comment above.

I would appreciate your help in answering the question below.

My question is: which section

should I cut off by 9 inches? Should I keep the metal

at 16 ft which would make the wood section shorter by 9 inches

or reduce the lower or middle section? Or

should I cut each section off by 3 inches?

[Designer]

Dale, I would take the 8" off of the 2 1/4' section.

[Dale Niemann]

Thanks Graham,

I will do it.

[Dale Niemann]

An update on the Alum tube to mast process.

The inside diameter of the 2.5" tube is too small to accept the 2.25" tube.

I spent some time using a small drum sander on a drill and was unsucessful. I took the tubes to a metalshop and they could not ream out the tube because it was too big for their machine. They suggested getting a hone. Specifically, a dingleberry hone. In trying to find one of these, I found they go by various names, china berry, rasberry, etc. They look like a hair brush, with wires with small sphere shapes of grinding stone at the tips. The only place I found one was at a NAPA Auto Supply store. However, they did not have the right size and the cost would have been about $70, so I gave that up.

A friend finally, came to the rescue. He had a friend in the auto engine repair business. He provided the hone shown in the attached photo. It did the job. However, it still took almost three hours of grinding to get the small tube to fit into the larger.

Next, I will Epoxy the tubes together.

[Dale Niemann]

Sorry, I am having trouble getting the photo to attach. It is too big. I will add it tomorrow.

[Dale Niemann]

Here is the photo. I am not sure what the name of this honing tool is. The three abrasive stone slides fit into the tube and expand outward to smooth and remove material VERY Slowly ( which is probably good).

[JeffM]

Dale, I can't figure out why they won't fit. The .25 inch difference in diameter, less the .065 (X2) wall thickness of the outer pipe, should leave you with .12 inch of air somewhere.

Is the reaming going to lower the strength? I suppose the double thickness of pipe, and the epoxy, will more than make up for it.

[Terry Dunn]

The outer pipe is .125"

[Roger Peterson]

Hi Dale,

I did the same thing with my mast sections and the hone from the auto store. I wrapped emory cloth (120 grit) around the hone stones to help speed up the process. I did kill my cheap Black & Decker drill motor in the process. It was worth the effort though because the fit is perfect. By the way, I bought the hone for $20 new.

[Dale Niemann]

JeffM, Terry is correct. I purchased the 2.5 inch tubes with 0.125 wall thickness. Also, on this size wall they do not guarantee the wall thickness like they do on the smaller sizes.