Gray cone- (Finishing carbon graphite edges) RESPONSES
Randy McFarland
Description
Collection
Title:
Gray cone- (Finishing carbon graphite edges) RESPONSES
Creator:
Randy McFarland
Date:
7/25/2005
Text:
ORIGINAL QUESTION
Gray buffing cone
What have you found that works well to buff carbon graphite laminations?
What is your source? (Our Trautman turns at 3450 RPM.)
Randy McFarland, CPO
RESPONSES (thanks to those who took the time!)
Wet hand sanding is best.
Without doing an hour length lecture....here goes.
Carbon (or glass fiber) composite - hard to grind
Shouldn't be heated when grinding
3M or any abrasive supplier can give you appropriate material HOWEVER it
seems to not be usually used in P&O as they are also generally
expensive. (grinding material should be stronger than what's going to
be ground)
(Hint: it should cut through the fiber/resin lamination like
butter...therefore no heat rise. Most sanding papers etc that are used
will deteriorate very quickly)
There are finishing materials for the Cut surface (trim line) which
can include polishing and sealing. At worst polish and seal with the
resin matrix already used.
Do not grind into the surface or into high stress area. Preplan layout
of fibers to minimize discontinuity at trims..and gee I think the
Trautman is going fast...going to hard to grind
without significant temperature rise if you just used conventional
sanding blocks etc... (Always wear protective mask)...or give up and
take up smoking.. ;-
The best buffing of the graphite sockets are done in sequence using 3
different tycro cones then with 200 grit wet sand paper go along the
edge
and remove any excess carbon. This method leaves a very fine and smooth
edge. sometimes I will use a lacquer to seal the edge if its real thin.
I've never found anything that works as well as 125 grit sand screen.
After smooth sanding with the trautman, it takes a minute or so of hand
sanding and its as smooth as you'll want it to be.
I ran this question about 2 years ago and discovered from the list that
sand screen under the tap in the sink works great.
fine sand cone followed by 440 wet sandpaper by hand
I use a very fine grit wet/dry sandpaper - I sand it dry and by hand
after getting the edge as smooth as I can with a fine cone. Clean the
edge with acetone on a cloth.
The cones that I order can be ordered from Friddle Orthopedic , Cascade
Orthopedic or Pel Supply. There are three red is the course, then fine
in
blue?green, then finer in green. The course finer and finer tycro wheels
and
cones are similar but the trick is that once you have a nicely rounded
edge
to then go to the hand sanding otherwise it starts to fray and you end
up
with a rough spiky edge.It is also important that your lamination is
wicking
well so that you have resin to buff too much vacuum will cause the same
problem when finishing.
If your reply to me comes back undeliverable, please forward that
error message to our IT guy, Bruce.
His E mail is: <mailto:<Email Address Redacted>> <Email Address Redacted>
Gray buffing cone
What have you found that works well to buff carbon graphite laminations?
What is your source? (Our Trautman turns at 3450 RPM.)
Randy McFarland, CPO
RESPONSES (thanks to those who took the time!)
Wet hand sanding is best.
Without doing an hour length lecture....here goes.
Carbon (or glass fiber) composite - hard to grind
Shouldn't be heated when grinding
3M or any abrasive supplier can give you appropriate material HOWEVER it
seems to not be usually used in P&O as they are also generally
expensive. (grinding material should be stronger than what's going to
be ground)
(Hint: it should cut through the fiber/resin lamination like
butter...therefore no heat rise. Most sanding papers etc that are used
will deteriorate very quickly)
There are finishing materials for the Cut surface (trim line) which
can include polishing and sealing. At worst polish and seal with the
resin matrix already used.
Do not grind into the surface or into high stress area. Preplan layout
of fibers to minimize discontinuity at trims..and gee I think the
Trautman is going fast...going to hard to grind
without significant temperature rise if you just used conventional
sanding blocks etc... (Always wear protective mask)...or give up and
take up smoking.. ;-
The best buffing of the graphite sockets are done in sequence using 3
different tycro cones then with 200 grit wet sand paper go along the
edge
and remove any excess carbon. This method leaves a very fine and smooth
edge. sometimes I will use a lacquer to seal the edge if its real thin.
I've never found anything that works as well as 125 grit sand screen.
After smooth sanding with the trautman, it takes a minute or so of hand
sanding and its as smooth as you'll want it to be.
I ran this question about 2 years ago and discovered from the list that
sand screen under the tap in the sink works great.
fine sand cone followed by 440 wet sandpaper by hand
I use a very fine grit wet/dry sandpaper - I sand it dry and by hand
after getting the edge as smooth as I can with a fine cone. Clean the
edge with acetone on a cloth.
The cones that I order can be ordered from Friddle Orthopedic , Cascade
Orthopedic or Pel Supply. There are three red is the course, then fine
in
blue?green, then finer in green. The course finer and finer tycro wheels
and
cones are similar but the trick is that once you have a nicely rounded
edge
to then go to the hand sanding otherwise it starts to fray and you end
up
with a rough spiky edge.It is also important that your lamination is
wicking
well so that you have resin to buff too much vacuum will cause the same
problem when finishing.
If your reply to me comes back undeliverable, please forward that
error message to our IT guy, Bruce.
His E mail is: <mailto:<Email Address Redacted>> <Email Address Redacted>
Citation
Randy McFarland, “Gray cone- (Finishing carbon graphite edges) RESPONSES,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 5, 2024, https://library.drfop.org/items/show/225124.
