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knottyBuoyz
02-15-2010, 10:31 AM
Anyone cut their own tape from rolls? I've got a line on some cheap fiberglass in rolls that I'd use to make tape. Anyone got any ideas on which method to cut the rolls would work best?

BBSebens
02-15-2010, 10:56 AM
I envision a large rolling blade. Big enough to reach the depth of the roll. Spin the roll and push the rolling blade into the roll. if the roll is tight enough, it ought to work out. Tape it up so it doesn't unravel. This also assumes the tube can be cut as well. if its cardboard your ok. otherwise your going to have to re-roll it onto something else.

Ian McColgin
02-15-2010, 11:23 AM
NO. I'll all be unravelling edges.

Even where the material seem manageable this is a horror outside the factory. Like the time I had the bright idea to stretch my masking tape by turing a 2" wide roll into 2 1" rolls.

When I was making new sails for Granuaile, I had the tape for tabling made by the cloth company, letting their industrial strength hot cutters do the job. That leaves edges that don't unravel. On small jobs, I've made my own tape by unrolling some and cutting, hot knife if the material would melt, and that works. Even natural fibres that must be cut, not melted, won't unravel that much while you work.

But glass. What a mess. If your soul really really recoils at just buying some rolls of suitable tape, unroll a sheet, tape the strike line, pin the thing down, mark the line accurately, and cut either by disposable blade against a steel edge or sheres if you don't mind runining them and leaving a wavey cut.

G'luck

P.I. Stazzer-Newt
02-15-2010, 11:33 AM
I can foresee a claim for selvedge

Once more into the fray

knottyBuoyz
02-15-2010, 11:52 AM
The only reason I ask is I have an opportunity to buy some obscenely cheap (high quality) fabric. I also need about 600' of tape for my project. At going rates that's about $700 Cdn to buy the tape required. I can get a 100 yd roll of fabric for $225 that'll produce five times that amount if I can cut it! I could take the 600' I need and sell off the other 2400' to offset some the costs of my materials.

I was thinking about a diamond wire saw in a continuous loop powered off a pulley mounted to a small motor. :confused:

kc8pql
02-15-2010, 12:00 PM
As noted above, it's not the cutting, it's the unraveling. You're going to end up with a huge mess and will end up buying real tape anyway.

Mike Vogdes
02-15-2010, 12:08 PM
I never had any luck making tape out of fabric... big mess. Your tape specs are probably pretty heavy anyway if its a stitch and glue design. Not a good place to cheat.

boattruck
02-15-2010, 01:01 PM
KB, I'm with the rest of the gang, you may save a dime to shoot yourself in the foot, the advantage of the tape is the lack of endless un-raveling fibers. If you must, buy the cloth and warehouse it till a project comes along that can use it, Cheers, BT

wizbang 13
02-15-2010, 01:17 PM
or just use larger(403) filets and no tape.(gonna get my ass cut for that one)

JimConlin
02-15-2010, 01:20 PM
A guaranteed mess. Selvege edge glass tape is cheap.
4" 8 oz tape is $24 for 50 yd. roll from Fiberglass Supply (http://www.fiberglasssupply.com/Product_Catalog/Reinforcements/Glass_Fabrics/glass_fabrics.html)
Not nearly enough saving to worry about.

Double Bias stitchmat is commonly slit for tape, but it's done by the distributor.

Candyfloss
02-15-2010, 02:45 PM
It is double bias cloth isn't it?. You should only use EDB for taping.

wizbang 13 Re: Cutting a roll to make tape
or just use larger(403) filets and no tape.(gonna get my ass cut for that one)

But I love this idea.

knottyBuoyz
02-15-2010, 03:00 PM
I just got a call back from the guy. It's 1708 biaxial so I don't think it'll work. If ya don't know ask eh?

Candyfloss
02-15-2010, 03:13 PM
There are no "made" tapes in NZ. All tapes are cut from the roll by the importers, so far as I know, and by all appearances, on a bandsaw. Presumably with excellent extraction! Want me to research that? It'll only take a phone call.

knottyBuoyz
02-15-2010, 04:46 PM
There are no "made" tapes in NZ. All tapes are cut from the roll by the importers, so far as I know, and by all appearances, on a bandsaw. Presumably with excellent extraction! Want me to research that? It'll only take a phone call.
I would appreciate that Candyfloss! Thnx.

Tom Robb
02-15-2010, 05:38 PM
Hey, go for it. Post pix.
Winter is starting to drag and I expect we could all use the laugh.

Boatsmith
02-15-2010, 05:44 PM
Raka has a machine that cuts any width tape off a roll. I use a lot of 1708 tapes and Larry cuts them to whatever width I want. Unravelling has not been an issue. I believe the machine is
similar to two bread knives conversely reciprocating. David

Bill Huson
02-15-2010, 08:46 PM
If the roll glass is real cheap - unroll, tack it down, and cut "tape" of your desired width on a bias, as in 45 deg angle. Hardly any unraveling problem, and the angled strands go into and around tighter corners.

knottyBuoyz
02-15-2010, 09:21 PM
Raka
has a machine that cuts any width tape off a roll. I use a lot of 1708 tapes and Larry cuts them to whatever width I want. Unravelling has not been an issue. I believe the machine is
similar
to two bread knives conversely reciprocating. David
I believe this is what I'm looking for. Bosch industrial foam cutter.

http://www.cpotools.com/bosch-1575a-foam-rubber-cutter/bshn1575a,default,pd.html?start=1&cgid=bosch-foam-rubber-cutters

Although $350 will buy a lot of fiberglass tape! They do work though.

http://www.boatdesign.net/forums/attachments/materials/31762d1242487287-cutting-fiberglass-help-required-glass-cut1.jpg

kc8pql
02-15-2010, 09:21 PM
...and as usual on the wb forum, you can count on getting answers that are 180 deg. apart. :confused:

kc8pql
02-15-2010, 09:26 PM
See all those little strands sticking out on the cut end? When you apply the sticky resin and smooth out the glass, it pulls the strands loose and leaves them sticking out all over the place.

http://www.boatdesign.net/forums/attachments/materials/31762d1242487287-cutting-fiberglass-help-required-glass-cut1.jpg

Boatsmith
02-15-2010, 09:37 PM
For structural tapes we use 45/45 biax.the strands unravel quite a bit less.

kulas44
02-15-2010, 11:38 PM
I have cut fiberglass cloth into strips/tape using a bandsaw, after tightly wrapping the cloth in butcher paper and tape. I do not reccomend it. Leaves loose edges, strings fall out when you try to use it, all around not real good. And, occasionally, the band saw will get a big bite, pull a wad of fibers into itself and generally fubar the whole mess.

tomlarkin
02-16-2010, 12:40 AM
For structural tapes we use 45/45 biax.the strands unravel quite a bit less.
Biaxial tape is also much better structurally if you're filleting or joining parts. You get twice as many fibers crossing the joint as straight-line tape.

john welsford
02-16-2010, 01:01 AM
Hey Candyfloss, Fiberglass Supplies in Albany, Adhesive Technologies and Epiglass all sell "made " tapes in various weights, constructions and widths. You may not find them in some retail stores but all three of those will have a selection.

John Welsford ( in Hamilton)


There are no "made" tapes in NZ. All tapes are cut from the roll by the importers, so far as I know, and by all appearances, on a bandsaw. Presumably with excellent extraction! Want me to research that? It'll only take a phone call.

john welsford
02-16-2010, 01:07 AM
Try cutting across the roll at 45 deg bias. The tapes that you make will stretch if you pull on them but they are fine if handled carefully.

John Welsford


See all those little strands sticking out on the cut end? When you apply the sticky resin and smooth out the glass, it pulls the strands loose and leaves them sticking out all over the place.

http://www.boatdesign.net/forums/attachments/materials/31762d1242487287-cutting-fiberglass-help-required-glass-cut1.jpg

Candyfloss
02-16-2010, 03:54 AM
There seems to be a language difficulty here. That picture is NOT of double bias cloth. That is boatcloth.

"EDB": E stands for glass (I don't know why!) DB for double bias. Double bias means two layers of fibers laid over each other at 45 deg. to the run of the cloth and stitched together along the length of the fabric. It is not a woven cloth.

Biaxial cloth is made the same, but includes a chopped strand mat on one surface, also stitched in.

"CDB" is carbon double bias. There are others, but I have never used them.

I would never use boatcloth tapes for structural laminating. They are much too messy, hard to get round corners, & nowhere near as strong for the same weight as double bias. We only ever used boatcloth as a protective layer, usually over wood or ply.

As John points out, bias-cut boatcloth will stretch all out of shape. The stitching in EDB prevents this.

Typhoon
02-16-2010, 04:49 AM
I have cut fiberglass cloth into strips/tape using a bandsaw, after tightly wrapping the cloth in butcher paper and tape. I do not reccomend it. Leaves loose edges, strings fall out when you try to use it, all around not real good. And, occasionally, the band saw will get a big bite, pull a wad of fibers into itself and generally fubar the whole mess.

I played that game with a 50m roll of Polyester mesh. It kinda worked well enough, fortunately, the job didn't require a perfectly straight, presentable edge......
I wouldn't do it again.

Regards, Andrew.