Thread: Lathe Bedding Mortar

cement powder and water mix?

Originally Posted by .RC.

cement powder and water mix?

I did wonder about a strong sand cement mix, but I did not know if it would be suitable.

The other thing I though of was ceramic tile grout.

The main purpose (in my mind anyway) is to fill the imperfections in the concrete surface and to entice the 10mm plate to sit flush against the bottom edge of the lathe base.

The lathe has threaded holes for adjustment screws in 6 positions from memory. Do I make screws or use shims? I will try to measure the threads today. Roughly 25mm diam and a fine thread.

Dean

Originally Posted by Oldneweng

The other thing I though of was ceramic tile grout.

Most of the tile grout you see in the box stores is made by a company called Davco. They do a machine grout called 702 dura bed.

http://www.lanko.com.au/lanko/images...ril%202006.pdf

Places like Bunnings could get it, if they stock Davco Tile grout. The special orders desk would be the place I'd ask.

Do you have a concreter's supply company nearby. They will have something similar. Its used to butter in tilt slab constructions.

The stuff I use is called Epirez 5 star grout. I get it from a place called Kencor sales. They have a branch in Bendigo. But Epirez is part of the ITW group - Ramset, Devcon, Molybond, Permatex, Galmet etc. Places that stock those products, like my local Industrial supplier can get it. Last I bought was about $23 bucks for a 20 litre bag.

Regards Phil.

The adjustment threads seem to be M24 fine. I would like to try one before going too far. It is difficult to get a good reading from the holes.

What grade of material should be used?

Dean

just use an expanding grout.

lots available...bostik, sika, parchem, ramset etc should be available from good bunnings or the bigger mitre10 stores

Thanks for the suggestions guys. I will make some more enquiries. Sometimes all you need is a name.

Dean

For what you've described I'm assuming you're going to lay the plate on a bed, let it harden and the position the lathe? I'd use tile adhesive under the metal plate(s), laid with a 5mm notched trowel if it's relatively uneven, smaller notches if it's smooth. Tile adhesive is cheap. The notches will allow the plates to be levelled properly, you don't need 100% bearing, but if tapped down you'll be close anyway, and if you've ever tried to level something where it's just slapped in a mortar bed you'll understand why the notches are needed.

If for some reason you can't get tile adhesive, mix mortar as 2:1 sand cement, wet and sprinkle a light dusting of cement powder before laying the bed. I generally squirt in some cross-linked PVA glue (ie exterior) to any cement based mortar/render mixes I use as it helps keep it a bit more flexible and will help to resist cracking with movement or if you feather out an edge. You can buy commercial bondcrete if you're feeling wealthy, but the MSDS implies to me it's something similar to PVA glue, looks and feels the same too. It should help prevent wicking of moisture up into the steel, but don't quote me on that as I've never used it specifically like that.

I'd suggest priming the plates first with a good zinc based etch primer to help prevent rust, the preferable a good paint to protect the surfaces. Concrete/mortar retains a significant amount of water.

I have plenty of tile adhesive, but I had discounted it because it is the polymer modified type which I thought would be too flexible. I have just had a poke at some that is accessible and has been down for several years. It is still rubbery. I guess that type is out. After a quick look on Google, all that seems to be mentioned is the flexible type.

I can always go with the mortar idea. I have some Bondcrete. It can be used to create a barrier, but painting the steel would not hurt. I also have numerous notched trowels. Thanks for these ideas.

Dean

_{I don't think that adhesive you have sounds particularly suitable Dean, I was thinking more along the lines of a standard cement based floor adhesive for rigid substrates. By the same token, a small amount of flexibility when poking a small section probably isn't going to count for squat when considering bedding a whole machine on it, but if in doubt just bed it in sand cement mortar as mentioned. That's the old school method of laying floor tiles anyway. Bondcrete isn't essential it's just what I always throw in (well actually PVA) as above. It adds to the workability and costs bugger all in the grand scheme of things.}