I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

On 17 Dec 2003 19:53:05 -0800, (Richard
Nienhuis) wrote:

I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.

You should look he www.westsystem.com for tech info.These guys are
a great resource and won't BS you about what epoxy can and cannot do.
The products are outstanding also.

The other big name in epoxy is System Three www.systemthree.com .
I can't comment on System Three's products, but I have seen one of the
company's officers post on a wooden boat forum and he tends to gloss
over some of the better know limitations of epoxy.

You should be aware that curing epoxy generates a lot of heat- enough
so that it could catch fire in the mold. That would be bad.
I'm sure the tech guys at WEST system know how to safely cast large
amounts of epoxy.

I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

It won't be cheap- WEST System epoxy is about 40.00 USD a quart.
For two gallons, figure on $400 with shipping, three gallons $500.
That's closing in on a complete mill from Harbor Fright.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?

Any good marine supply.

-Carl

"Richard Nienhuis" wrote in message
om...
I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

If you can get your hands on a copy of the June, 2000 issue of Machine Shop
Guide, we ran an article on the subject there ("Cast Polymer Machine Tool
Bases"). It isn't as technical as you may like but there's lots of basic
background info, including the names of the three US companies that make the
bases on contract.

There are a few other points: The epoxy you want for this job is not the
laminating or repair epoxies made for boats. You don't need their adhesion
quality and you don't want their high exothermic rates. I don't have a
source to send you to but look for *industrial* sources of casting epoxies,
not laminating epoxies such as WEST System or System 3. You'll save a bunch
of money, besides.

Your idea for the aggregate sounds reasonable. They use multi-graded
aggregates of granite or quartz in the commercial jobs, with one builder
stating they grade their aggregates from near-dust to pieces roughly 1/2-in.
on a side.

If you're looking for a cheap but effective way to do this job, you may want
to consider using some form of concrete for the mass of material, possibly
with an epoxy/aggregate structure on top of it. Oh, and don't try using it
for a headstock. The thermal conduction is too low and you may run into
serious thermal distortion problems. Another point: commercial polymer bases
are built on shake tables. I've never handled a stone-filled epoxy mix
myself but it sounds like you have to shake it pretty good, more than you'd
want to try shaking regular concrete, to get good wetting.

Good luck. I used to write about concrete and polymer bases but it was many
years ago, when Studer was the only one using epoxy. The article I refer to
above was written by Frederick Mason. He's pretty thorough on his research.

Ed Huntress

On Thu, 18 Dec 2003 06:50:10 GMT, "Ed Huntress"
wrote:


There are a few other points: The epoxy you want for this job is not the
laminating or repair epoxies made for boats. You don't need their adhesion
quality and you don't want their high exothermic rates. I don't have a
source to send you to but look for *industrial* sources of casting epoxies,
not laminating epoxies such as WEST System or System 3. You'll save a bunch
of money, besides.

Gougeon Bros says WEST System can be cast (I've done it myself) and
mentions a Formula SAE car built with a carbon fiber intake that was
formed using the lost wax process (using WEST Sysytem epoxy, natch).
Gougeon Bros sells slow hardners to keep the curing temps from getting
out of hand.
But it ain't cheap.

Another point: commercial polymer bases
are built on shake tables. I've never handled a stone-filled epoxy mix
myself but it sounds like you have to shake it pretty good, more than you'd
want to try shaking regular concrete, to get good wetting.

Epoxy already has good wetting- I'll bet they shake the mix to remove
any air bubbles.

-Carl

In article , Carl Byrns says...

Epoxy already has good wetting- I'll bet they shake the mix to remove
any air bubbles.

For potting small items I use vaccuum to de-gas
the epoxy.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

"Carl Byrns" wrote in message
...
On Thu, 18 Dec 2003 06:50:10 GMT, "Ed Huntress"
wrote:


There are a few other points: The epoxy you want for this job is not the
laminating or repair epoxies made for boats. You don't need their
adhesion
quality and you don't want their high exothermic rates. I don't have a
source to send you to but look for *industrial* sources of casting
epoxies,
not laminating epoxies such as WEST System or System 3. You'll save a
bunch
of money, besides.

Gougeon Bros says WEST System can be cast (I've done it myself) and
mentions a Formula SAE car built with a carbon fiber intake that was
formed using the lost wax process (using WEST Sysytem epoxy, natch).
Gougeon Bros sells slow hardners to keep the curing temps from getting
out of hand.
But it ain't cheap.

Carl, using WEST system resin with a slow hardener for casting is like using
a Ferrari to haul trash to the dump. You can do it, and Meade and Jan would
love you for doing it, but it's not in your best financial interest. g


Another point: commercial polymer bases
are built on shake tables. I've never handled a stone-filled epoxy mix
myself but it sounds like you have to shake it pretty good, more than
you'd
want to try shaking regular concrete, to get good wetting.

Epoxy already has good wetting- I'll bet they shake the mix to remove
any air bubbles.

At least one that we talked to said it was to wet the stone. I thought it
was to compact the aggregate, actually, but the response was that it was for
wetting.

Regardless, they shake that thing.

Ed Huntress

On Fri, 19 Dec 2003 01:22:46 GMT, "Ed Huntress"
wrote:


Carl, using WEST system resin with a slow hardener for casting is like using
a Ferrari to haul trash to the dump. You can do it, and Meade and Jan would
love you for doing it, but it's not in your best financial interest. g

No doubt. But I have used WEST where I could have used 'something
else' because I trust the stuff.

Speaking of best financial interest, have you ever read their product
catalog? Some of the stuff is way overpriced- gloves, stir sticks,
mixing buckets...
Me, I use latex surgical gloves, craft sticks, and Cool Whip tubs (or
Jello snack-size pudding cups).


At least one that we talked to said it was to wet the stone. I thought it
was to compact the aggregate, actually, but the response was that it was for
wetting.

I'd buy compaction or de-aeration, but not wetting only because that's
what makes epoxy such a good adhesive- it'll stick to damn near
anything.
Also, Gougeon Bros says to be careful not to mix in air.

-Carl

"Carl Byrns" wrote in message
...
On Fri, 19 Dec 2003 01:22:46 GMT, "Ed Huntress"
wrote:


Carl, using WEST system resin with a slow hardener for casting is like
using
a Ferrari to haul trash to the dump. You can do it, and Meade and Jan
would
love you for doing it, but it's not in your best financial interest. g

No doubt. But I have used WEST where I could have used 'something
else' because I trust the stuff.

Speaking of best financial interest, have you ever read their product
catalog? Some of the stuff is way overpriced- gloves, stir sticks,
mixing buckets...
Me, I use latex surgical gloves, craft sticks, and Cool Whip tubs (or
Jello snack-size pudding cups).

Yes, everything is high-priced. But your statement above explains it. You
can trust those guys to do two important things: to tell you straight what
will work, how well it will work, or why it won't work; and to have tested
and experimented with everything they sell. If confidence in the materials
and processes weighs heavily on the project you're doing, you can count on
WEST System materials to do what they say they'll do.

I sailed with Meade and Jan in 1972, BTW. I was sailing every weekend at the
Bay City Yacht Club regattas in those days, and I sailed one of their DN
Class iceboats in the winter, as well. I have great respect for those guys.
They're real down-to-earth, practical engineers.

However, if you know the story of how the W.E.S.T. System became the WEST
System, you know that they didn't always get it right in the early days. g

Ed Huntress

Regarding shaking to get wetting and remove trapped air. I recently cast
some parts for a glass blowing glory hole in a refractory castable. The
recommended water/castable mix ratio leaves it very stiff but I used a
needle scaler to apply vibration and it transformed it. Without the
vibration the stiff mix is very difficult to compact but when vibrated
it consolidates very well. I cast in layers about an inch thick and
placed a wooden block on the mix then used the needle scaler on the
block and worked the block over the whole surface until most bubbles had
surfaced and the mix compacted.

Ed Huntress wrote:

"Richard Nienhuis" wrote in message
. com...

I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?


If you can get your hands on a copy of the June, 2000 issue of Machine Shop
Guide, we ran an article on the subject there ("Cast Polymer Machine Tool
Bases"). It isn't as technical as you may like but there's lots of basic
background info, including the names of the three US companies that make the
bases on contract.

There are a few other points: The epoxy you want for this job is not the
laminating or repair epoxies made for boats. You don't need their adhesion
quality and you don't want their high exothermic rates. I don't have a
source to send you to but look for *industrial* sources of casting epoxies,
not laminating epoxies such as WEST System or System 3. You'll save a bunch
of money, besides.

Your idea for the aggregate sounds reasonable. They use multi-graded
aggregates of granite or quartz in the commercial jobs, with one builder
stating they grade their aggregates from near-dust to pieces roughly 1/2-in.
on a side.

If you're looking for a cheap but effective way to do this job, you may want
to consider using some form of concrete for the mass of material, possibly
with an epoxy/aggregate structure on top of it. Oh, and don't try using it
for a headstock. The thermal conduction is too low and you may run into
serious thermal distortion problems. Another point: commercial polymer bases
are built on shake tables. I've never handled a stone-filled epoxy mix
myself but it sounds like you have to shake it pretty good, more than you'd
want to try shaking regular concrete, to get good wetting.

Good luck. I used to write about concrete and polymer bases but it was many
years ago, when Studer was the only one using epoxy. The article I refer to
above was written by Frederick Mason. He's pretty thorough on his research.

Ed Huntress

I don't think you can just use any old epoxy. Some of them shrink
quite a bit when curing. Turcite, Moglice, and Belzona are resins that
may be used.

http://groups.yahoo.com/group/Lathe_2000/files/ has some pictures of a
small lathe cast in resin.

(Richard Nienhuis) wrote in message . com...
I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

I use a LARGE amount of West and other general purpose and laminating
epoxies. (approaching 250 gallons) I would NOT use any of them for
casting. The curing reaction is very exothermic. In masses larger than
a couple of cubic inches it gets hot enough to boil and will foam up.
Even the slowest set laminating hardeners will do it. Excess heat also
greatly weakens the final product.

Casting epoxies are a lot cheaper and don't generate as much heat but
straight resin/hardner still can't be cast more than about 3/4" thick.
Resins used for thicker sections use an aluminum filler to help disburse
the heat. With the high volume of granite you can probably double the
thickness without a problem but I would make a test panel about a foot
square first.

If you can't get the full thickness without excessive heat buildup you
can do it in two pours. Cast the first layer about 3/4" thick and let
it cure until the surface just looses its tack. That point is the start
of the "B" cure. The exothermic stage is over and the epoxy is very
brittle but still chemically active. You can then set your dovetails
and pour the top layer. Because the first pour is still chemically
active you will still get molecular linkage and it will form a
monolithic slab. If you wait more than 8-10 hours between pours you are
SOL. The bond will be mechanical only. Also an amine wax builds up on
the cured surface that must be washed off with lots of water and the
surface must be sanded with 80 grit to get some tooth.

Fiberglass Coatings Inc. sells a tabletop epoxy for $30/gallon that
would probably work. http:/www.fgci.com I would call their tech
support to make sure 800-272-7890

Richard Nienhuis wrote:
I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

In article , Richard Nienhuis
says...

All the agregates will be soaked in silane ...

Silane?? What's that all about?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Silane. Yeah, I noticed that. The mind reels. If he really means what he
says, I hope he's a looong ways away from Portland Oregon.

-- Greg


"jim rozen" wrote in message
...
In article , Richard
Nienhuis
says...

All the agregates will be soaked in silane ...

Silane?? What's that all about?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article , Greg Dermer says...

Silane. Yeah, I noticed that. The mind reels. If he really means what he
says, I hope he's a looong ways away from Portland Oregon.

-- Greg

For the rest: Silane is SiH4 if I'm correct. It's
a gas frequently used in semiconductor manufacture,
and is both toxic and pyrophoric, which is to say it
ignites spontaneous in the presence of oxygen.

The 'soot' is, of course, sand.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

"jim rozen" wrote in message
...
In article , Greg Dermer says...

Silane. Yeah, I noticed that. The mind reels. If he really means what
he
says, I hope he's a looong ways away from Portland Oregon.

-- Greg

For the rest: Silane is SiH4 if I'm correct. It's
a gas frequently used in semiconductor manufacture,
and is both toxic and pyrophoric, which is to say it
ignites spontaneous in the presence of oxygen.

The 'soot' is, of course, sand.

Ed the Anti-Chemist here, but silane treatments for glass fabric are simple
water-based rinses. They improve the bonding between organic and inorganic
materials. Fiberglass cloth intended for bonding into composites with epoxy
or polyester are usually treated with silane.

My guess is that it's extreme overkill for the application in question.

Ed Huntress

I should have said a silane solution. Silane is a decent adhesion
enhancer for epoxies.


jim rozen wrote in message ...
In article , Richard Nienhuis
says...

All the agregates will be soaked in silane ...

Silane?? What's that all about?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
snip

This is the only one to use.

http://www.phillycast.com/welcome.htm

"Richard Nienhuis" wrote in message
om...
I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

Not exactly DIY, but Zanite http://www.zanite.com/ manufacture large items
from epoxy and silica (quartz).
Martin

--
martindot herewhybrowat herentlworlddot herecom

I'll follow up the many helpful messages here.

So I will be sure to find some casting resin with a slow hardener.
Another method of cooling for very large castings is to have some
parting compound loaded copper pipes running thru the piece to get rid
of some more head. The shaker table is something I can probably rig
together quickly. The silane solution, well maybe I'll use it if I
don't get good results. I planned on doing a small test block.
Hopefully this will work out.


(Richard Nienhuis) wrote in message . com...
I've been looking around the net for information on how epoxy/granite
machine bases are formulated. So far I have come up with very little.
I'm going to attempt to make a smallish mill with a somewhat homebrew
epoxy formula. If anyone knows anything about these sorts of things
feel free to speak up.

For the base material I'm using the folowing formula:

First I will use quartz rock etched with a moderately strong HCL
solution.
The stones will consist of 1/2 to 1 inch stones.
For fine filler I will try a mix of 90% quartz sand and 10% carbon
fiber.
All the agregates will be soaked in silane and dried before being used
as filler.

For the mold I will use varnished wood. The steel dovetails will be
set directly into the epoxy plum.

Some problems I have a
Where can I get 2 or 3 gallons of epoxy and enough hardener?
I need to find some cheap ground dovetails.

I am probably going to need to make a couple small test batches. If I
cure the epoxy under heat and vacuume is there anything I can use to
seal it to reduce water uptake?

Anything else anyone can think of?

In article
,
says...
I'll follow up the many helpful messages here.

So I will be sure to find some casting resin with a slow hardener.
Another method of cooling for very large castings is to have some
parting compound loaded copper pipes running thru the piece to get rid
of some more head. The shaker table is something I can probably rig
together quickly. The silane solution, well maybe I'll use it if I
don't get good results. I planned on doing a small test block.
Hopefully this will work out.




The real stuff from Philadelphia Resins, which someone else
mentioned, is not that expensive. IIRC, it's less than
$1/lb for a kit which includes the proper resin &
aggregate.

Ned Simmons