Epoxy-Granite machine bases (was Polymer concrete frame?)

[jhudler]

How about building a flat torsion box and then level it.
I do all my woodworking assembling on one that measures 4x6 feet made of 3/4 MDF with a hard replaceable Masonite inlay.

For a level surface you only have to level the box with adjustable feet.

You must have a well aligned table saw to make one: blade parallel to guides that are parallel to the fence, and blade that is square to table.

A torsion box would be an excellent surface to cast EG parts on.

Google "torsion box"

Jack

[ckelloug]

Howdy all,

My new building is acquired and the city has signed the first of two inspections for the electrical in my workshop! I'm on the way towards real data!!!!!

Congrats to Walter on the pour of the Tabletop epoxy. I still think it would be easier to use the 37-127 and 37-606 as the surface as it's much lower viscosity will allow it to level better.

For metalworking precision, I disagree with Larry that you can mill the spoilboard to match the beam. If you rotate the cutter more than a tiny fraction of a degree from exactly parallel with the spoil board, when you mill them to one another, you will get a bunch of regular and unremovable ridges, the severity of which will depend on the size of the cutter.

As for the torsion box idea, it may solve wood working problems and make an okay base for a surface plate but I doubt however it will get the kind of precision required to build large metal parts accurately. It's a good start but I think it's an insufficient end.

--Cameron

[walter]

DIY Epoxy-Granite surface plate






Yay! this is exciting!

[jhudler]

As for the torsion box idea, it may solve wood working problems and make an okay base for a surface plate but I doubt however it will get the kind of precision required to build large metal parts accurately. It's a good start but I think it's an insufficient end.

--Cameron

He was looking for a flat and level place to work.
I've had almost 1500 lbs on mine with only .005 deflection. I wouldn't leave that load on there very long because wood stretches.

[lgalla]

Walter sure is exciting.If I may quote Martin,what about"Sporty"?
Larry

[jhudler]

Sporty! Damn he forgot the pretty woven Carbon Fiber mat!!! Redo!

[jhudler]

After mixing a dozen or so EG formulas I can say this:
You know you have the correct packing in the formula when you can easily mix it with 10% epoxy.

[walter]

By volume?

[jhudler]

yes, by volume

[jhudler]

Add 1/6 by volume the following:

• #6 Agsco Brown
• #4 Agsco Quartz
• #2 Agsco Quartz
• #2/0 Agsco Quartz
• G800 Zeeospheres
• G200 Zeeospheres

Add 10% resin based on the volume of aggregates, after mixing and tamping. Stir in resin and vibrate until throughly wetted.
It is much faster and easyer if you use BYK-A 525 air release additive at 0.5% and BYK-W 969 Wetting agent at 2%.

So if you have 150 ml of aggregate you add 15 ml resin, 0.075 ml BYK-A 525, and 0.3 ml of BYK-W 969. Have your pipette's ready for the last bits .

It's not an exact science therefore, if the mix is too clumpy then add a few more ml of resin until it combines.

Jack

[walter]

Sporty! Damn he forgot the pretty woven Carbon Fiber mat!!! Redo!

lol Jack

How about that borosilicate glass.. Are you going to try it? Personally, I think it's a pretty cool idea.


Larry,

Remember the channels? http://www.cnczone.com/forums/showpo...&postcount=195

they're back..





I'm trying to match the curvature of the earth lol

[jhudler]

lol Jack

How about that borosilicate glass.. Are you going to try it? Personally, I think it's a pretty cool idea.

[jhudler]

The other day I was finger joining some wood and the thought hit me that this would make an excellent bit to create bonding grooves in aluminum way beds.

http://www.rockler.com/product.cfm?O...Select=Details

[harryn]

He was looking for a flat and level place to work.
I've had almost 1500 lbs on mine with only .005 deflection. I wouldn't leave that load on there very long because wood stretches.

Hi, I missed that the torsion box idea was for me. Anyway, it would be nice, but out here in CA, there are no basements, not enough yard room for a workshop, and a just big enough garage to get by. I don't own a table saw or drill press - no room. That is why the router has to do double / triple duty, even if that means it is "not the right tool" sometimes. I am trying to get away from doing everything by hand.

Thanks for the idea though.

Walter - double checking - did you obtain that flat surface (I know with the fan stuff) with just gravity settling ? Now I wonder if I should just pour a thin EG layer on the garage floor - maybe 1/4 - 1/2 in thick.

I need to go back and look - maybe I can just pour some of that epoxy that is being used in the EG formulation on the floor and let it cure as is.

I was searching for some info on self-leveling epoxy, and noticed that Dupont makes a fluorosurfactant under the Zoryl brand. The purpose is to reduce surface tension (so it will flow flat better, etc) There are a number of variations of this material for specific applications, but what was most interesting, is that the general chemical family is not so different than synthetic vacuum pump oil.

http://www2.dupont.com/Zonyl_Foraper..._techinfo.html

I did a quick scan, and it looks like the FSH formulation is probably closest to epxoy use.

[jhudler]

Speaking of "Sporty"...

Has anyone any experience with Gelcoat?

Love this EG stuff but like Ford said "You can have any color you want, as long as it's black".

Looking at molding something large and would like another color other and black.
As someone mentioned before (Larry?) any mold release you use is just sanded off.
So it seems that Gelcoating the mold and adding a thin mat of fiberglass would alleviate this problem. Not to mention a "Sporty" looking color. Gelcoat can be clear so the mat could be a nice sporty looking twill weave carbon fiber fabric.
Any problems with this? Pointers? Products?

What about something called "Tooling Gel Coat", can this be used to coat the interior of a wooden mold?

I read that Gelcoats cure anaerobically and require that it is backed with resin and reinforcement mat. Is this always true?

Jack

[lgalla]

Harryn,I would not bother searching for leveling epoxy for your floor.Precision Epoxy already has it figured out.3X6'should not cost too much.It is not a good idea to use the E/G resin as an ESP[epoxy surface plate] as TT{table top epoxy}is formulated for the task and has air release addatives etc.If you use laminating or casting resin for an ESP,you may get amine blush which is a waxy cloudy surface.Your high gloss plate will not be glossy after a few days cure.
Good stuff Walter.You have been very busy.
I might add on torching or the heat gun.They are only to release air not to provide faster curing.As soon as you don't see air bubbling out stop using the torch or gun.
What about trying vibration to level?
Larry

[jhudler]

I need to go back and look - maybe I can just pour some of that epoxy that is being used in the EG formulation on the floor and let it cure as is.

Just remember that floor when wet will be slicker'en snot!

[lgalla]

Jack,The German guys were having release problems probably from vibrating the aggregates and it acting like sandpaper on the mold surface.Walter solved the problem with sandwich wrap or some of the plastic materials mentioned before.
Polyester gellcoats must be backed up,say in this case your 635 resin with a glass cloth,carbon fiber,etc.
Tooling gelcoat is for master molds.It is extremely hard.Yes you could coat a wooden mold if it is sealed well and waxed.
Sporty color?Just add pigment to the resin.
Larry

[ckelloug]

Harryn,

Thanks for the zonyl info. Zonyl FSH in not suitable for epoxy use though other zonyl formulations are. It is for aqueous solution which epoxy is not. I am not trying to be critical as Zonyl is good info, I just want to keep a bunch of zonyl FSH samples out of the waste stream. Dupont is also harder to get samples from than other vendors. (added via edit It looks like Zonyl FTS is the one that would work for our application.

I've got samples of 3M Fluorosufactants Novec 4430 and Novec 4432 which are suitable for use in epoxy. 4432 is the most wetting fluorosurfactant in the 3M line. Jack also had a wetting agent from BYK which I hand't considered.

I'm busy getting E/G stuff out of my kitchen and into my new building so I'm monitoring the discussion but haven't got much to add right now.

Also, Harryn, are you going to be around the week of December 12? I'm going to be in the bay area for my day job part of that week and the following week.

Walter and Jack,

Kudos on your surface plate and tests respectively. I am totally excited about what you guys are reporting and am waiting with baited breath to get started doing instead of pontificating!



Regards all,

Cameron

[jhudler]

Sporty color? Just add pigment to the resin.
Larry

The Zeeospheres are a pigment. Unless we use the White version of Zeeospheres then we'd have a chance of using other colors. There's no W-810 so we'd have to do another formula.

Guess I'll experiment with this too.