Midspan supports? And oil for non stainless steel?

Building a 3’ x 3’ work area Primo which ends up with 4’ length tubes. I’m using 1" steel tubing with .049" walls. What can I use to support the outside rails (hopefully without drilling?). And what options do I have as to oiling it so it won’t rust?


Search Thingi for something like ‘MPCNC rail support’ and you should find several choices. For rust prevention a good non-silicone paste wax like the seemingly available everywhere (at least in the US) SC Johnson’s seems to be the preferred choice.


I used wax to coat my DOM steel. No sign of rust yet and I think that if I re-coat/polish every few months I should have no problem.

I used MinWax .

Mike B

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Do you have a link to the wax?


My thingiverse is bugging out, any chance you have a link to one? https://drive.google.com/file/d/1GOq_nR1nxiPzai1KaQdgP_8xM4bBcklO/view?usp=sharing is this the wax?

Here are some I found: Span Support Generator for MPCNC rails by spiffcow - Thingiverse

Mpcnc support leg by Rcmn - Thingiverse

I haven’t felt the need so didn’t study them too much.

The link for the wax won’t open for me, I only suggested that particular wax as I know it’s readily available at Lowes/Home Depot if you’re in the US. I’d just look for a paste wax containing no silicone which can be a problem if it gets somewhere that may see paint and/or glue.

Link for SC Johnson paste wax
minwax is similar

we used this in the military for floor polishing.

Doesnt take much, very light coat, let dry and buff off with clean rag.

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I got tool wax from Lee Valley, but there are plenty of options.

I have many rust prone tools. Probably so do you already.

Anything with a machined surface, like a tablesaw, bandsaw, drill press… That’s usually bare cast iron, which will rust badly if not cared for. Cutting tools like chisels, or shears. Many hand tools like wrenches or sockets have a non chromed cast iron or steel surface.

They tend not to rust, because they tend to be kept clean and dry. If you take a cloth to your steel rails once in a while, you’ll probably be fine. If you want to be able to leave it for a long time, then the tool wax will do the trick.

A cheaper option is light mineral oil. You can get it in the pharmacy. A light application of that will work for a very long time. Just put a little on a paper towel or clean rag and lightly wipe the surface. This also makes a nice woodworking finish, so it’s doubly useful.

I’d have chosen 0.065" wall tube myself… Oh wait. I did. Anyway, I had intended to run mid-span supports for the long rails (37" addressable) but so far I haven’t installed them. I’m not having any sag issues, so it hasn’t become a problem yet. I have printed a set that use some threaded rod for adjustability, but haven’t screwed down the base for the support yet. I’ll get to that… At some point…

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