[burdickjp]

I was thinking about ways to stiffen my Sieg X2 column and thought about filling it with one of the available engine block cements. That I'm aware of, these are cements with iron mixed in. They're used to fill the water jackets of racing engines. It has similar enough properties to cast iron for that application.

I haven't found anything discussing these kinds of materials in this application. I would thing this would have the advantage of being machinable as well. I'd like to machine a channel where the current Z-axis rack is and install a lead screw there for improved Z-axis accuracy. I think if the column were filled this would not sacrifice much rigidity in doing this.

[bhurts]

I don't know if it will work but it looks like a reasonably safe bet compared to some of the epoxy granite mixes.

Ben

[awerby]

The question is whether it shrinks or not. If it does shrink away from the sides of the column, then it won't stiffen it. An expanding cement might be better.

[chevydyl]

I don't think it shrinks. If it did it would be squeezing the cylinders around the pistons in an engine block causing possibly a 'cold' seize. I like the idea. I wonder about its self leveling properties. Just my thought on it I haven't done any reading about it but have heard of it. Good idea to use it for the mill column. I'd call their tech support and ask some questions.

[bhurts]

I did some reading before my first post. It is iron filled concrete so machining is iffy. As for shrinking it claims not to shrink away from the waterblocks it's used to fill. It also claims to hold up to the vigors and heat produced by the large engines it's used for as well as strengthening things.
All and all I think it's well worth a try.

Ben

[burdickjp]

The mixes I've found involve water. Some sources say water involved mixes leave pores which are less than ideal. Moroso specifically calls theirs a cement grout. Maybe an epoxy iron mixture would be more appropriate?
Of course, instead of machining after setting I could use a mold which would leave a cavity for the lead screw, or just forget about running the lead screw in the column altogether.

I think I'm going to give something like this a try.

[chevydyl]

Sorry my phone double posted.

[burdickjp]

I've found quite a few iron filled epoxies. Most claim good machinability and have a linear shrink ratio of less than 0.002:1. That sounds promising. They look rather expensive, so the engine block filler may be more economical, but I could likely add some grey cast iron filling as well by cutting up an engine block.

Here's a few I'm looking at:
Hapcast 3738 - HAPCO Inc.
BCC BC7053 | Northern Composites | Process & Structural Compsite Materials
Epoxy Casting Resins Specifications at Freeman Mfg. & Supply Co
Casting Resins

[rbjem]

What about adding steel rods (kind of like rebar) for extra reinforcement?

[burdickjp]

What about adding steel rods (kind of like rebar) for extra reinforcement?

I have an excess of engine blocks to cut up, otherwise I'd be all about it.

[fxstc]

Any updates?

[burdickjp]

Any updates?

I got a job and moved states. It will be a while before I can put time into this.

[RFB]

I got a job and moved states. It will be a while before I can put time into this.

Back when I racing in Top Alcohol I used B 11 Hydra Cal to fill my engine block water passages. B 11 has a slight expansion when set up and the alkali prevents rust formation. If I was to use plaster for creating mass in a machine tool void then I think that I would use B 11 with well pack gravel. In other words a lo tech approach to epoxy granite. The density of the aggregate is what is need where harmonics and flex are present.

Ron