[Oldmanandhistoy]

While researching an idea for my next cnc router I came up with the idea of using Epoxy resin floor paint on MDF or Ply built cnc routers.

Has anybody else considered this idea?
Seams to me it would be a good idea for machines stiff enough to mill aluminium and would protect the machine from cutting fluids.

Not using floor paint on my own machine but thought it might be a good idea for others to consider.

Your opinions please.

[dertsap]

may work i ve considered trying it , it may stick to wood better than it does to concrete , it must stick to something , cause it didn t stick to my concrete very well , i got 3 gallons to use on something and it ain t goin on my floor to peel back again

[swarfmacdaddy]

The paint is no better than the substrate its going on. Also most importantly, you must have a good oil based primer first. Read the epoxy can for any special compatability rules. Good luck!

[Madclicker]

I don't think you can do anything to ordinary MDF to make it compatible with fluids. The slightest nick or imperfection in the surface will wick the fluids to the MDF substrate and swell it before you know it.

[Grandad]

I've done a few experiments with sealing MDF and found that the best method was to use a sanding sealer, (clear cellulose and talcum powder) well thinned down and brushed into every visible corner and hole of the MDF sufaces. The finish coat would be a good quality two pack polyurethane, sprayed on if possible. The polyurethane can resist quite a lot of of abrasion and bangs. Incidentally this is the finish that I will use on my masterpiece when it's finished.....Rod

[dertsap]

i painted my gantry with fibreglass resin , i ll do the rest soon enough , that stuff isn t the nicest to work with but where i m from it is wet for most of the winter season and everything gets the moisture into it out in my workshop , so far this has been my best solution

[Madclicker]

I've done a few experiments with sealing MDF and found that the best method was to use a sanding sealer, (clear cellulose and talcum powder) well thinned down and brushed into every visible corner and hole of the MDF sufaces. The finish coat would be a good quality two pack polyurethane, sprayed on if possible. The polyurethane can resist quite a lot of of abrasion and bangs. Incidentally this is the finish that I will use on my masterpiece when it's finished.....Rod

Try this experiment with the finish: Hit it with every tool that would ever be used near it in a machine 20 times and then soak iit in cutting fluid 12 hrs a day for a year.

IMO, the best finish for ordinary MDF is laminate, but i would never get it near cutting fluids and expect it to hold up.

[Grandad]

Try this experiment with the finish: Hit it with every tool that would ever be used near it in a machine 20 times and then soak iit in cutting fluid 12 hrs a day for a year.

IMO, the best finish for ordinary MDF is laminate, but i would never get it near cutting fluids and expect it to hold up.

I don't think the average DIY router built using MDF would survive very long in the environment you are describing no matter what the finish.

MDF routers are at best a good compromise between cost and capability and as such should be treated with a certain amount of care. The finish that I described would probably resist the knocks and bangs that any hobby machine would receive during its relatively short working life very well. The fact that the first coat of very thin celullose sealer penetrates the MDF sufaces gives a measure of protection against humidity even if the finish coat is damaged. As you say the use of cutting fluid in large doses is definitely not recommended but since I wouldn't cut metals on an MDF machine for me the problem doesn't arise.

To change the subject a bit have you, or any body out there had any experience with a Bosch GGS 27 straight grinder. I bought one this morning for 118 Euros (140 Dollars) as a substitute for my Dremel and it looks good only 500w power with 6mm collet... opinions please....Rod

[ger21]

To change the subject a bit ....

Please don't take threads off topic. Always start a new thread when you have a new question. Thanks.

[ger21]

I brushed a coat of West System epoxy on my MDF gantry sides. IMO, it seals far better than any paint wood and makes it much easier to get a nice paint job afterwards.

As for soaking any MDF in any water or waterbased fluids, only do this if you want to throw away you parts and make new ones. Unlike hardwood and some plywwods, which can sometimes tolerate getting aa litle wet, water and MDF don't mix. The MDF will swell up, and start to fall apart.

Here's West Systems recommendations for an epoxy moisture barrier, from their website.

Apply a minimum of two coats of WEST SYSTEM epoxy for an effective moisture barrier. Apply three coats if sanding is to be done. Moisture protection will increase with additional coats, up to six coats or about a 20-mil thickness. Additives or pigments should not be added to the first coat. Mixing thinners with WEST SYSTEM epoxy is not recommended.

[Madclicker]

I don't think the average DIY router built using MDF would survive very long in the environment you are describing no matter what the finish.

That was my point. This thread was started with the proposal that a coat of floor paint would make MDF stand up to cutting fluids. MDF needs to be sealed and there are a lot of ways to do it. I use laminate and red oak on my machine.

[dertsap]

if you look at the toll coolant takes on a cnc mill or lathes paint job , there isn t much a guy can do to protect mdf from flood coolant , but can protect it enough to be resistent if a guy is using a spray bottle , a keep on wiping of the excess coolant , best thing to do is make a sub table to take the abuse , to protect the actual machine , and in all reality you don t need coolant or oil to take light cuts in aluminum
outside moisture is what worries me

west system epoxy is bullet proof but ugly to work with , i built a stitch and glue boat with it last year TOUGH STUFF

[see2nen]

I used it on my plywood coolant tray after I fiberglassed the plywood. It seems to work well.

[Oldmanandhistoy]

Hi all

Nice to see this topic is getting some interest.

I should have been clearer, I have noticed in a few threads talk about cutting thin sheet aluminum on a MDF cnc router and the recommendation of using a little WD 40 to aid cutting. I can see that using flood coolant would not be an option on such a machine.

As Ger21 mentioned it would be IMO as well far superior to most paints.

P.s. Bosch grinder

John.