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WHAT IS THE BEST WATY TO CUT "GLASS"

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WHAT IS THE BEST WATY TO CUT "GLASS"

Old 12-30-2005, 10:26 PM
  #1  
marwen1
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Default WHAT IS THE BEST WATY TO CUT "GLASS"

Well, it's been a long time in coming but it's time to finally attck the fibreglass side of finishing.
I will the very first to atate that MONOKOTE & I are not the best of friends. At least not to my standards.

When I cut glass , and right now I have some ZPOXY and some 1.5oz & some .05oz glass.

If I cut with scissors, it is a staticey mess and the edges are a joke.

I have always read to cut on the bias. I fully realize that. Whet I cut with a new, sharp razor blade, it cut reasonably well in one direction but TERRIBLE in the other. So I have to assume that the glass I buy from the LHS is already cuy biased.

About the only way I can think of cutting inventory, is to use a hot knife, the same as I do with f111 nylon ripstock (parachute material)

I don't have a "hot knife" right now so if that's the way to go, I'll have to go out and get a fairly decent one. (I hate tools that are 1/2 baked)

Any input?

marwen
Old 12-31-2005, 02:51 AM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Your two fingering is a bit off tonight judging by the spelling mistakes....

Sharp scissors is best. By sharp I mean REALLY sharp. Dress the ones you have with a very fine file and then stone the bevel. A light pass over the face to remove the burr and you should be good for a while. The fiberglass does take the edge down fast but if the scissors are decent quality steel they'll easily last for at least one project before needing resharpening.

If you try to cut it with a blade then it may work OK for a short while but soon the blade will dull and start pulling and then you'll REALLY have a mess and a half.
Old 12-31-2005, 06:09 AM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Holy COW Bruce:

I see what you mean. LOL

Late last nite, the pain from the old arthitis was really acting up and all I wanted to do was get that post on-line.

I saw the VERY 1st one in the heading after I'd hit the ENTER buttom but I didn't even see the "junk" in the first sentence until just now.

Thank you so very much for your patience!

I was going to give you a call on the landline and ask you directly but -- no, it's the holidays. Go the route!

Funny, your answer. I must have a pile of scissors around here but I think I would hurt my hair if I tried to use them an anything but paper. Of course, in the average household, paper is the quickest way dull an edge.

I had priced out some really good haircutting shears earlier this month so that my wife could give me a haircut whenever I wanted one but all I could find was stuff in the $50 range.

A couple of days before Christmas, my little seven year old daughter and I did our final shopping for Mother in a local Wal-Mart store. As we passed the watches and other stuff like that I asked a clerk if they had any hair cutting shears. For $15 (or so) they handed me a pair with a LIFETIME guarantee on them. My goodness, I can cut off, no, SNIP off ONE little strand at a time. So I asked them if they had and "thinng" shears. Same brand, same price, same overall size, and the same guarantee, too.

So-o-o-o, that being the case, I'll give them a try on my glass. If OK, then I'll jump right up there and get me another pair today an place them into the tool box. This way, I won't be robbing Mothers pair!

I don't have a clue in the world how to sharpen them. I have read the facts till I'm blue in the face, but it never seems to want to work out.

Thanks again Bruce. HAPPY NEW YEAR to you and all of your loved ones.

Marshall
Old 12-31-2005, 11:00 AM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

The best way I have found to cut fiberglass cloth is using a rotary cutter and a cutting mat. Both can be purchased in the sewing section of Walmart. Yeah I know, what are you ding in the sewing section of Walmart... I was Truly amazed at the edge I get using this method!

Jerry
Old 12-31-2005, 11:39 AM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"


ORIGINAL: marwen
When I cut glass , and right now I have some ZPOXY and some 1.5oz & some .05oz glass.

If I cut with scissors, it is a staticey mess and the edges are a joke.
Cut the 'glass an inch or so larger than the surface being covered, to provide an 'overhang' that will be sanded off after the epoxy has fully cured.

It doesn't really matter that the cut edge is frumpy 'cuz it won't be the finished edge on the model.

When you apply the epoxy, not matter how hard you try, you'll have pull-out along the edge of the 'glass, so having an excess overhang means that the ragged edge is really a "don't care".
Old 12-31-2005, 11:43 AM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

I use one of these. Iit works a charm with the cutting mat:
http://www.misterart.com/store/view....&group_id=7261
Old 12-31-2005, 02:41 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Ooooo... some interesting hints coming out here.

Jerry, what weight of cloth have you cut using the rotary cutter and matt? I can see it for the light stuff but wonder how it would work for the 4 oz/sq yd and up thickness. A great hint in any event.

Fred, that's a great hint too. I do it that way when I make stuff in glass but it sure doesn't hurt to re-mention it. I also find it helps to more or less jab with the resin brush at the edges rather than brush in strokes. Disturbs less of the short fibers that way.

And an Very, Very Happy New Year to Marwen and everyone else out there as well as all your families.
Old 12-31-2005, 03:11 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Well, I tred the very sharp pair of brand new scissors . I'm still getting loose edges if I handle the fabricvery much.

Yes, I get a nice clean cut but I'm afraid that what I have been told about the mfg packaging this stuff already cut on the bias is hokey.

I'm using the SIG brand of glass right now.

I'm really surprised that no one likes my idea of using a "hot knife". It's nothing more than a soldering iron with about a 1/16" x 14" wide blade screwed into place where the normal tip is. Once you simply "touch" the fabric it makes a cut and sears the open edge closed. The hotter the tip, the faster you can cut your material. It DOES have a tendensy to make the edge thicker because it has melted the glass, but if we have an overhang anyway - what the difference?

Q) If I want to cover just a very small specific area, do I cut it to size, or do I still cut it oversize and let the adjacent piece go OVER its seam area?


marwen
Old 12-31-2005, 03:32 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Marwen, the glass cloth is literally made from fibers of actual glass. A hotknife would have to reach white hot before it'll cut the glass fibers.

It may be partly your method with the scissors. When cutting paper or other cloth we all tend to push the scissors forward and into the material to get some extra cut for each stroke. I found that with glass cloth it's important to either remain totally stationary or even lightly pull back with the scissors while closing the blades. It also helps to add a little twist to the already natural action between the two handles to force the blades more firmly together. Glass is hard to cut and wants to pry the shearing blades apart. It takes a bit more force on the handles trying to rub the blades more firmly to avoid this.

You think glass is bad? Try cutting kevlar cloth with scissors! ! ! ! ! They MUST be sharp like I mentioned before and even then the stuff requires a lot of sideways pressure and still takes off the edge in only a few feet from all but the very best steel.
Old 12-31-2005, 07:54 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

I use the rotary cutter on 6 and 8 oz fiberglass and it works great!

[sm=thumbup.gif]Another great trick to keep the glass from unravelling is to spray the area you are going to cut with hair spray. Use a light misting of the cheapest spray you can find. Keeps the cut edges in place while you are working with it and the spray does not affect the epoxy or polyurethane you are sticking it down with.

[sm=rolleyes.gif]The spray also seems to kill some of the static electricity on the very light glass cloth.
Old 12-31-2005, 10:00 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

I glad I took the time to read this thread. I like the rotary cutter idea.
Old 01-01-2006, 07:40 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Bruce: ... and the very best of a Happy New Years to you and as well, your family!

Back in the late 80's, I was cutting & sewing F111 (parachute stock) into DRAG CHUTES.

The parachute rigging shop had about an inch or so of 1/8" KEVLAR wrapped around a 12 inch long wire spool. We were good customers so he simply gave me what was left for free. I guess there wasn't enough left to use as a full blown chute chord.

If I recall, it was rates at 400lb. We couldn't cut it with scissors, a razor, knife -- nuttin'!

Even the HOT KNIFE trick wasn't the best, but at least it did make its way through it - after MANY passes. Oh yea! KEVLAR is nuts to work with.

Thanks for all the help and cutting ideas. I'm quite sure there are tons more.

Hah! Keep thats cards & letters comin' folks.. LOL


HAPPY NEW YEAR

marwen
Old 01-02-2006, 12:48 AM
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marwen1
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

HAH! That $15 pair of haircitting shears did the trick!

S-m-o-o-t-h a cut as can be. Now the trick is to see how long it'll keep their edge.

marwen
Old 01-10-2006, 08:08 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Well, the .5oz glass went on pretty fast and it really beefed up the fuselage.

The wings were made solid as were the tail feathers, so I ran as many holes as I could into the tail and I cut out the center of the wings leaving about 3/8" border. I installed some short "ribs" to help with its integrity, glassed basically the wings (top only) and the tail. I took my time anf lo & behold MONOKOTE & I actually came out OK

suggestions on the MONOKING please

marwen
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Old 01-10-2006, 11:24 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

Looking spiffy. I'm looking forward to hearing about the full sized one and it's flights.
Old 01-10-2006, 11:56 PM
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Default RE: WHAT IS THE BEST WATY TO CUT "GLASS"

I just tonite, started to work on the MONOKOTE.

Hey Bruce: do you recall that I'd said that the 36" PORT wing was heavier than the other?

I waws looking at it -- STRAIGHT - ON earlier tonite and (looking at it from the front) the left wing was absolutely 90Ëš - where it should be... I noticed that the other had a slight dihedral.

If I'm not mistaken, that would give it reason to want to "fall off" to one direction moreso than the other.

Ever so slightly now that I've done a pile of "balancing"

As I hold it by the very wing tips - regardless if its right side up or up side down -- it rotates so that it sits in a positive attitude.

Even with that, it feels like its still tail heavy.

With the weather like it is, I can't even test this thing till springtime.

Hell of a hobby - ain't it?

marwen

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