Does hide glue crack with age ?
Does it become brittle, like cascamite ?
If using for a skin layer this could be a problem?
Steve.
Does it become brittle, like cascamite ?
If using for a skin layer this could be a problem?
Steve.
It is what is used in Stradivarius violins for example, and they still seem to hold together ok 🙂
Don't think you need to worry about it for a few centuries at least, it is very tried and tested and known for being stable over time.
Leob.
But it is used as a glue not as a skin.
Cascamite is a very strong glue but when I used it as a thin skin it cracked.
They also mention on some sites something about surface crackling effects over time ?
Steve.
But it is used as a glue not as a skin.
Cascamite is a very strong glue but when I used it as a thin skin it cracked.
They also mention on some sites something about surface crackling effects over time ?
Steve.
I have always presumed that this was the exciter panel resonance ?
It can be useful for adding low frequency to a panel when using for acoustic music, as long as there is no loud electronic sub bass, which will cause my exciters to rattle if not braced.
Not sure if Cascamite is known to age that well, seems like the opposite looking at discussions online with many reports of glued joints becoming bad over time.
Hide glue can be used to create a crackling effect in combination with other paint, but that happens directly during drying.
Whet it has dried completely after a day or so, it will be very stable over time.
Hide glue can be used to create a crackling effect in combination with other paint, but that happens directly during drying.
Whet it has dried completely after a day or so, it will be very stable over time.
Leob.
If you coated the canvas panel, would it bend withered the material or would it snap or crack ?
Steve.
If you coated the canvas panel, would it bend withered the material or would it snap or crack ?
Steve.
Took a piece of the 10mm plate with double coats, and the plate breaks while the skin is intact on the side I'm being towards. I the broken off piece then dangles in the skin and can be bent back and forth seemingly endlessly. No cracking when pressing together the plate either, but starts to look like wrinkled skin instead.
I would describe the skin as very similar to an extremely thin hide. The shellacked side on the other hand crackles.
Just remembered my daughters old school violin needs repairing.
Her children would love to play with it.
This could be my excuse to buy some hide glue 😀
I'm always interested in better materials.
I will see how it goes at my local shop ?
Steve.
Her children would love to play with it.
This could be my excuse to buy some hide glue 😀
I'm always interested in better materials.
I will see how it goes at my local shop ?
Steve.
Leob .
I've been looking on line, and I can only find 15kg/m3 graphite eps.
I think this is about equal to my 70grade eps ?
But you have to add about £40 delivery!!
Steve.
I've been looking on line, and I can only find 15kg/m3 graphite eps.
I think this is about equal to my 70grade eps ?
But you have to add about £40 delivery!!
Steve.
It seems like grade 70 of EPS is a UK thing. Here it is 60 or 80, which is 15 and 17 kg/m3. So I guess grade 70 would be 16 kg/m3.
I linked earlier to the place I bought from: https://www.dekokopf.com/neopor-styroporplatten-3er-set-50x33x2-5cm.html
Was a cheap way to order some different varieties of EPS to Sweden at least, but not sure how different it is to the one you get from building suppliers. I'm really happy with the sound of the plates, with the 25mm Neopor being a favourite, but seems all of them lack a bit in response above 10k.
Leob.
25kg/m3 is pretty hi density.
You should be reaching 20k , no problem ?
Even my low grade eps but with a pva coating reaches 20k.
Steve.
25kg/m3 is pretty hi density.
You should be reaching 20k , no problem ?
Even my low grade eps but with a pva coating reaches 20k.
Steve.
I am up unusually early today, a bit off illness has contributed.
The Link is a UK Supplier with a graphite eps - 10mm @ 150g per m2.
https://www.insulationshop.co/10mm_grey_polystyrene_ewi_graphite.html
The Link is a UK Supplier with a graphite eps - 10mm @ 150g per m2.
https://www.insulationshop.co/10mm_grey_polystyrene_ewi_graphite.html
JohnnoG.
This is one of the sites I looked at and the density is 15kg/m3 equal to 70 grade .
Postage is an extra 40 or so I believe.
Steve.
This is one of the sites I looked at and the density is 15kg/m3 equal to 70 grade .
Postage is an extra 40 or so I believe.
Steve.
I know, but I don't 🙁
I tested same exciters using same tape to mount them on my Polycarbonate plates, and have plenty of response above 10k, so I can only conclude that the plates are the issue. It is the same on the regular EPS plates from the same supplier as well, to not a difference with the GPS specifically.
I would be curious to try the building supply GPS to see how it differs to the plates I have. Like I said in previous posts, the GPS is sounding tighter and less "chorusey" than the regular EPS. The EPS can add a nice shimmer to some material, but the GPS seems to give a more accurate sound.
But I have decided to invest in vacuum bagging now to make carbon composite plates, so wont do more styrofoam experiments for now at least.
Leon.
I would expect polycarbonate to have a rising response anyway,so is not probably a good comparison.
Can you show a frequency response of the graphite panel at 30cm in front of the exciter ?
Steve.
I would expect polycarbonate to have a rising response anyway,so is not probably a good comparison.
Can you show a frequency response of the graphite panel at 30cm in front of the exciter ?
Steve.
JohnnoG.
I made some measurements of the proplex panel.
Pic 1.
1 inch in front of exciter.
Pic 2.
To the right along the flute lines at the end of the panel at 1inch.
Large hump in response before roll off.
Pic 3.
Is at the bottom at one inch going across the flutes.
more even response before dip at 10k.
Pic 4 .
Was interesting which was at about 3inches from the corner on the bottom.
Stronger hf.
Pic 5.
The flutes are circular for added strength I presume.
Steve.
I made some measurements of the proplex panel.
Pic 1.
1 inch in front of exciter.
Pic 2.
To the right along the flute lines at the end of the panel at 1inch.
Large hump in response before roll off.
Pic 3.
Is at the bottom at one inch going across the flutes.
more even response before dip at 10k.
Pic 4 .
Was interesting which was at about 3inches from the corner on the bottom.
Stronger hf.
Pic 5.
The flutes are circular for added strength I presume.
Steve.
Attachments
This site has an interesting video of how the make eps and different samples.
https://www.custompac.co.uk/polystyrene-cut-to-size
Very expensive to buy single sheets , but cheep if bought in say 20s , delivery works out at about £100 !
I think I'll stick with wickes 70grade I think it has gone up in price a bit to about £11 for 8ft x 4ft.
I cut it up to get it in the car, but you can get a 8ft x 2ft which is easier to cut and costs a little less.
This is a very cheap panel and if treated properly gives a very good easy to drive sound with very good hf.
Steve.
https://www.custompac.co.uk/polystyrene-cut-to-size
Very expensive to buy single sheets , but cheep if bought in say 20s , delivery works out at about £100 !
I think I'll stick with wickes 70grade I think it has gone up in price a bit to about £11 for 8ft x 4ft.
I cut it up to get it in the car, but you can get a 8ft x 2ft which is easier to cut and costs a little less.
This is a very cheap panel and if treated properly gives a very good easy to drive sound with very good hf.
Steve.