I want to make some fiberglass antenna parts that would probably most easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of square
stock and make a diposable cutting tool for this.

Jimmie

"Jimmie D" wrote in
:

I want to make some fiberglass antenna parts that would probably most
easily be make by turning fiberglass rod in my lathe. Ive never done
this before and was wonder how rough fiberglass would be on the
tools/lathe. I have a piece of 1- 1/4 inch fiberglass rod I want to
turn down to fit the inside diameter of a piece of 1-1/4 inch tubing.
Im thinking get a piece of square stock and make a diposable cutting
tool for this.

The only tools that I have used to cut GRP have been carbide tools.

You need to consider the dust hazard.

Owen

Jimmie D wrote:
I want to make some fiberglass antenna parts that would probably most easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of square
stock and make a diposable cutting tool for this.

Jimmie


I've cut and machined a fair amount of Extren (pultruded structural
fiberglass composites) and things like glass-epoxy laminate over the years.

- cutting glass fibers makes tools dull in a big hurry, even carbide,
the wear rate is spectacular.
- diamond tooling survives quite well and isn't all that expensive
- or, just buy cheap tools and throw them away after a couple uses
(e.g. drill bits)
- the dust is quite obnoxious and abrasive, avoid getting it in the
ways or anything that needs high precision. lots of liquid coolant
helps keep the dust to a minimum
- breathing the dust is bad, getting it on your skin is bad, getting it
on your clothes is bad. Consider wearing one of those disposable tyvek
coverall suits. Try and keep the dust from spreading, because
inevitably, you'll pick it up later, and it itches, if nothing else.

- these are the reasons why machine tools used to machine glass or
carbon reinforced composites sell at a discount.. they wear out fast..
all those little abrasive particles grind away at all the precision parts.

Unless you're going to be doing a lot of it, you might be better off
just paying a machine shop that handles the stuff to do it for you.
Places that regularly machine laminates and composites have all the dust
collection stuff and tooling, and factor the wear into the price structure.

When I started working with composites at a former employer, they had
only done machining on conventional metals and plastics. After my
little foray into composites, they decided it wasn't worth it. Metal
scrap is easy to manage, little bits of glass fiber isn't.

On 24 Apr, 22:46, Owen Duffy wrote:
"Jimmie D" wrote :

I want to make some fiberglass antenna parts that would probably most
easily be make by turning fiberglass rod in my lathe. Ive never done
this before and was wonder how rough fiberglass would be on the
tools/lathe. I have a piece of 1- 1/4 inch fiberglass rod I want to
turn down to fit the inside diameter of a piece of 1-1/4 inch tubing.
Im thinking get a piece of square stock and make a diposable cutting
tool for this.

The only tools that I have used to cut GRP have been carbide tools.

You need to consider the dust hazard.

Owen

You sure do. I didn't notice it at first until a ray of sunshine came
thru the window and it could be seen swirling in the air.
Art

On Apr 24, 9:22 pm, "Jimmie D" wrote:
I want to make some fiberglass antenna parts that would probably most easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of square
stock and make a diposable cutting tool for this.

Jimmie

You didn't mention if it's a metal lathe or a wood lathe. If it's a
metal lathe, it should be no problem getting a good uniform diameter.
For one-off or just a few you can use either a HSS or carbide tool.
Protect the lathe parts, especially the bed, from the abrasive dust.
If you're worried about breathing the dust, keep the piece wet while
you're turning it. You probably don't need to, but you can sand the
tool marks out if you really want.

Your last sentence makes me think it may be a wood lathe. You should
be able to do ok with that too. Be careful about the tool digging in
and grabbing, of course. If you really don't want to try a standard
wood lathe tool on it, you could perhaps make one from an old (or
cheap) file; it would be a lot harder than a random piece of square
steel stock. Another possibility is a HSS metal lathe bit, mounted in
some suitable holder.

I certainly wouldn't think twice about turning fiberglass in a metal
lathe, with proper protection.

Cheers,
Tom

On Wed, 25 Apr 2007 00:22:16 -0400, "Jimmie D"
wrote:

I want to make some fiberglass antenna parts that would probably most easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of square
stock and make a diposable cutting tool for this.


I do a lot of fiberglass work. Building a 335 MPH airplane. The two
most important points are the dust is quite hazardous which pretty
much mandates wearing a good mask and not the little disposable paper
or cloth ones. The filter needs to be very fine. As has already been
said, you want to keep the dust off you and your clothes. The other is
the dust is abrasive and you do not want it to spread. I use a "whole
shop" fan with a large filter set close to the work so the draft
carries the dust right into the filter. You also need to protect the
ways and moving parts on the lathe. Good bits have already been
discussed.

Remember that the resin is sensitive to UV light and unprotected with
degrade rapidly. Also the glass fibers are easily damaged by water
(which was a surprise to me) so the finished piece needs a good coat
of paint, or varnish to provided protection from both UV and moisture.

Jimmie

"Roger (K8RI)" wrote in message
...
On Wed, 25 Apr 2007 00:22:16 -0400, "Jimmie D"
wrote:

I want to make some fiberglass antenna parts that would probably most
easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of
square
stock and make a diposable cutting tool for this.


I do a lot of fiberglass work. Building a 335 MPH airplane. The two
most important points are the dust is quite hazardous which pretty
much mandates wearing a good mask and not the little disposable paper
or cloth ones. The filter needs to be very fine. As has already been
said, you want to keep the dust off you and your clothes. The other is
the dust is abrasive and you do not want it to spread. I use a "whole
shop" fan with a large filter set close to the work so the draft
carries the dust right into the filter. You also need to protect the
ways and moving parts on the lathe. Good bits have already been
discussed.

Remember that the resin is sensitive to UV light and unprotected with
degrade rapidly. Also the glass fibers are easily damaged by water
(which was a surprise to me) so the finished piece needs a good coat
of paint, or varnish to provided protection from both UV and moisture.

Jimmie

Thanks Roger, probably didnt do it right then, I used some old high speed
steel tools and duct taped the shop vac to the tool holder. I was just
cutting down a fibeglass rod join two pieces of Al tubing together. It
really dulled the heck out of the tool. but I got it done. I was thinking of
mixing up a little resin to seal the raw edges and give it a coat of
automotive acrylic enamel to finish it off. I work with fiberglass encased
antennas I find they wil last seemingly forever if you keep them painted.

Jimmie

On Sat, 28 Apr 2007 16:53:00 -0400, "Jimmie D"
wrote:


"Roger (K8RI)" wrote in message
.. .
On Wed, 25 Apr 2007 00:22:16 -0400, "Jimmie D"
wrote:

I want to make some fiberglass antenna parts that would probably most
easily
be make by turning fiberglass rod in my lathe. Ive never done this before
and was wonder how rough fiberglass would be on the tools/lathe. I have a
piece of 1- 1/4 inch fiberglass rod I want to turn down to fit the inside
diameter of a piece of 1-1/4 inch tubing. Im thinking get a piece of
square
stock and make a diposable cutting tool for this.


I do a lot of fiberglass work. Building a 335 MPH airplane. The two
most important points are the dust is quite hazardous which pretty
much mandates wearing a good mask and not the little disposable paper
or cloth ones. The filter needs to be very fine. As has already been
said, you want to keep the dust off you and your clothes. The other is
the dust is abrasive and you do not want it to spread. I use a "whole
shop" fan with a large filter set close to the work so the draft
carries the dust right into the filter. You also need to protect the
ways and moving parts on the lathe. Good bits have already been
discussed.

Remember that the resin is sensitive to UV light and unprotected with
degrade rapidly. Also the glass fibers are easily damaged by water
(which was a surprise to me) so the finished piece needs a good coat
of paint, or varnish to provided protection from both UV and moisture.

Jimmie

Thanks Roger, probably didnt do it right then, I used some old high speed
steel tools and duct taped the shop vac to the tool holder. I was just

If the hose is in the right location the ol' Shop Vac should have done
a pretty good job at getting most of the dust, although I'd still
recomend a dust mask.:-)) I have a dust collector in the shop that
uses a 5" hose. (5th photo from the top
http://www.rogerhalstead.com/G3_file...s/glasair6.htm )

cutting down a fibeglass rod join two pieces of Al tubing together. It
really dulled the heck out of the tool. but I got it done. I was thinking of

Yah, the stuff is like trying to cut an abrasive wheel with a cutting
bit. :-))

mixing up a little resin to seal the raw edges and give it a coat of
automotive acrylic enamel to finish it off. I work with fiberglass encased
antennas I find they wil last seemingly forever if you keep them painted.

I've found the same. The original finish on the ones I've had here has
tended to be quite fragile and turns to dust in just a couple of years
which makes them very messy to handle. I prefer a two part acrylic or
cyanolic paint, but the plain old so called "epoxy" in a spray can
seems to work well. I only use white as the colors seem to get hot
enough to cause the resin to soften.

Roger (K8RI)




Jimmie