Finally some "proof" Interglas is a suitable alternative

[raiki]

Ok proof is probably not the right word but read on.

 

I have done some research, looking at datasheets and a heap of texts on fiberglass and so forth. With all the data avaiable I have produced the attached PDF which shows a comparison to Hexcel 7725/Integlas 92125 and Hexcel 7715/Interglas 92145.

 

Given the data shown I think the Interglas is definately a suitable alternative, which should help anyone building outside the US.

 

One thing you might be concerned about when looking at the data is the warp count of both the Interglas fabrics are MUCH lower than the equivalent Hexcel. What you need to know here is that the interglass "threads" are made up of multiple strands.

 

For example the BID: The Hexcel has 21 threads/cm whereas the Interglas only has 7. However the Interglas fibre is EC9-68x3 which means each major thread contains 3 strands. 7x3 = 21.

 

Also I only show one strength measurement, which I believe is tension. I figured there wasn't a lot of point looking for further data when the tension strength is very similar and the glass construction is basically the same from the same type of glass. I figure all other mechanical properties are going to be very similar.

 

One other thing I am concerned about is that the 7725 uses an 11 micron glass at a 204g weight and the Interglas uses a 9 micron fiber that has the same 204g weight. I don't know why two glass fibers of the same material but different diameters can have the same weight (given about a 40% volume difference???? This is in the Fill yarn (sideways). Either way the tension strength in that direction is as good (actually better) than the Hexcel.

 

The fill yarn is also slightly different on the UNI but I am not concerned about that because we dont rely on strength in that direction in the UNI.

 

Please do your own research but given what I have heared from others over the years and this data, I think Interglas is perfectly suitable.

 

Whether or not you intend looking at alternatives, this was a good educational experience for myself learning about the material that we are all betting our lives on (fiberglass in general). I'd suggest others do some research for the same reason.

 

http://www.canardzone.com/forum/attachment.php?attachmentid=1598&stc=1&d=1208513507

[raiki]

Oh, one other thing I learnt from all of this is that MGS is WAY superior to West System in almost all properties (in its cured state), so I have decided to not use West as I had originally intended.

[Cozy1200]

Oh, one other thing I learnt from all of this is that MGS is WAY superior to West System in almost all properties (in its cured state), so I have decided to not use West as I had originally intended.

Check your Checkbook out.

 

Only MGS 235 is available here and it's pricy. You may have $5-6 Grand in just epoxy. It is nice to work with though.

[brainfart]

The MGS285 prices you all have to pay seem ridiculous. The stuff is roughly the same price as West System in Germany, maybe a little more expensive. The other MGS resins are even cheaper than WS.

Ok, one reason is the current Euro to American peso exchange rate, but the hazardous shipping charges and all that add to the price, too. To make y'all a little more envious, epoxies including L285 are being shipped without any hazardous material surcharges here, are widely available from several suppliers, and it usually takes about 2-4 days for your order to arrive at your doorstep. Maybe we should set up some illicit L285 smuggling ring? Anyone interested?

 

Good news regarding the Interglas/Hexcel interchangeability, raiki. The weight per area seem slightly different though, any comment on that?

[brainfart]

The attachment isn't working for me. Anyone else have the same problem?

[Steve Innova]

MGS 285 is available in addition to 335. I get my from CST composites.

[raiki]

Good news regarding the Interglas/Hexcel interchangeability, raiki. The weight per area seem slightly different though, any comment on that?

The weights, dry, are within about 10% so I am not too concerned about that especially because the strength is equivalent.

[Spodman]

MGS 285 is available in addition to 335.

The point is it doesn't seem to be available HERE...

 

I can't follow the link either, message says it is an invalid type of link:confused:

[raiki]

I can't follow the link either, message says it is an invalid type of link:confused:

Guys, it used to work but for some reason no longer (it is a PDF file). I have just emailed Jon so I'll see what he can do with it.

[raiki]

Try this one.

Glass Comparison.pdf

 

Oh, and no complaints about mixing up metric and US standards.

[raiki]

Now a picture. What you see here is Hexcel BID in the bottom of the picture overlaid on Interglas at the top of the picture. You can see the cut line of the Hexcel in the middle of the picture from left to right.

 

 

Combine this picture with the PDF from my last post and I think you can agree that Interglas is good to go (BID).

 

I need to thank Dick at IronBark for the Interglas samples and Drew Champlin for the Hexcel samples. Thanks guys.

 

I am still working on the UNI. The samples I have are slightly different so I want to verify #s before I post details.

[Cozy1200]

...and Drew Champlin for the Hexcel samples. Thanks

You're welcome. And think Charlie Chaplin, like from the old B&W days.

 

Try the drape test. Make sure they can both bend over a fairly sharp radius at the same rate. I'd hate to see what happens if it doesn't bend as well as it should.

[raiki]

Try the drape test. Make sure they can both bend over a fairly sharp radius at the same rate. I'd hate to see what happens if it doesn't bend as well as it should.

Good idea Charlie, oops I mean Drew.

 

What I have just done is got a plastic container with a rectangular shape and draped each cloth over it (top and 4 sides) without distorting the fibres too much. The difference between the two are neglible, but the pieces I have are quite small so conisider the test only a small data point. I'd consider the edge radius and corners to be much like the map pockets.

 

Either way it was no more difficult to drape either cloth to the same shape, and the fibre distorsion in the compound curve areas where much the same.

 

One thing I have noticed is that the Interglas "handles" better. What I mean is it distorts less when moved, ie from bench to workpiece. All fibres maintaining a straight line until told to do otherwise (within reason). However the interglas sample I have was cut fresh off the roll, while the Hexcel has had Drews grubby mitts molesting it. For that reason I wouldn't say it was neccesarily better.

 

At this stage I would be happy to use either cloth. I am thinking at this point I might get some local Interglas and do chapter 3. I remember how Drews confidence piece felt very strong, so I will see how this compares. I doubt I'll test it to destruction but if I am having a bad day and feel like breaking something, then maybe so.

 

Drew, what hardener are you using? I will be getting MGS L285 from Dick but unsure of which hardener at this stage.

[Cozy1200]

Drew, what hardener are you using? I will be getting MGS L285 from Dick but unsure of which hardener at this stage.

I typically use 1/2 Fast & 1/2 slow. I use all slow on larger layups.

 

Because I've been using the slow harder faster than than fast, I'm currently using a larger ratio of fast to slow the consumption of the fast. Got that?

 

If I would order again, I would use only slow. It hot enough here in OZ, (especially up north in QLD) that curing by the next day shouldn't be a problem. Coming into winter, it'll be interesting to see how much the cure time if affect. It was about 50F out in the shop this evening.

[stevemew]

Hi All,

I just joined the forum and have recieved Cozy Plans #1559 so am raring to go. The question I have is do I just buy all this stuff from Spruce direct or spend the time sourcing this stuff locally. CH3&4 for example :

 

CH3 & 4

 

BID Fibreglass RA7725

BID Fibreglass RA7715

Urethane Foam

L335 MGS Epoxy Resin

H335F Hardener Fast

H335S Hardener Slow

H45 PVC Foam (30mm X 1M X 2M)

H100 PVC Foam (30mm X 1M X 2M)

Last-a-foam

Finnish Birch

Cotton Flox

Microspheres

2024T3 Sheet 2" X 4" X .2"

Machine Screws MS24694-S

 

Where do I get this stuff in QLD or Aus for that matter ?

and

Is it competative with spruce (after shipping etc..)

 

Any advice greatly appreciated ...

 

Rgds

 

Steve Mew

Brisbane

Cozy MK IV #1559

[longez360]

All,

 

MGS L285/H285 available in Vic from Ironbark Composites, torquay - Worth every penny. Sensational laminating room temp cure resin system. This is the system I recommend.

 

Araldite K3600 is a reasonable resin system with similar structural properties. Half the cost of 285. There is a beautiful varieze being constructed with this system. Jabiru use it.

 

If you exchange materials from the plans recommended system are you testing to ensure that they are equivalent? Please be very careful. If you are not happy paying extra for the highest quality materials, slow the build down on your aircraft until you can afford the build rate with them.

 

Styrofoam is available throughout the country. Vary your slurry to give good peel strength. Some of these foams do not absorb slurry even though they are all 2lb density.

 

Be VERY careful with peel ply. If you use a different peel ply, the mechanical bond properties will change. Some peel plys are ultra smooth - Not good for secondary bonding, but great for other purposes... Prep for bond correctly for any secondary structural bond. It is imperitive.

 

Be safe!

 

Cheers

 

Wayne

[Spodman]

Hello Wayne, was yours the excellent Long I saw at Cowra last year at the SAAA do?

 

Can you or anybody else indicate where Interglas cloth can be procured? I can't find it anywhere outside the Fatherland...

[longez360]

You are probably referring to John Atkinson's beautiful aeroplane. Mine is http://www.ez.org/feature/F0411-1/F0411-1.htm

 

Don't know anything about interglas. Is the plans system that expensive these days? It builds a great aircraft. I operate my 360 Long EZ out to 1875 lbs MTOW and cruise at 200KTAS most places. Will an interglas Long EZ be capable of that?

[hombreux]

Hello
My name Is Nicolas, and I'm building an Eracer
I'm trying to find a local fiberglass cloths suitable for my construction.

I would like to check the caracteristics :
Has someone got the OLD hexcel 7715 and 7725 tech data sheets?
On the Hexcel website, the new hexforce 7725 and 7715 seems (breaking strenght)
stronger than before.(hexforce tech data). (Stronger than Interglas )
So I would like to check the rutan design's original fiberglass cloth caracteristics...
Thanks for the help
Nicolas

[Kent Ashton]

This Hexcel manual appears to describe the cloths. See about p. 67

http://www.hexcel.com/Resources/DataSheets/Brochure-Data-Sheets/HexForce_Technical_Fabrics_Handbook.pdf