turning a 5.5 inch thick batt of cotton into two 2.25 inch thick batts

[falafel]

somewhat of a strange question, but...

anyone ever try to cut ultratouch cotton insulation this way: take a 5.5 inch thick batt, and try to slice it into two 2.25 inch thick batts. (obviously working with a 2 by 4 ft batt)

in other words, turning a potential bass trap into two mid-high traps.

then after framing in light wood and wrapping+stapling in muslin, put em over the kit.

i tried sharp scissors and a machete so far, and haven't got the cut i'm looking for... don't really wanna buy any special tools either...

of course i know the correct answer is just compress the 5.5 inch stuff as much as possible into about 3 inches and wrap it tight, hang 2 or 3 inches above the kit.

this is what i'll probably end up doing, but since i already hacked away at a piece, i thought i'd see if anyone else has ever tried to cut cotton this way.

cot cutton!

[Glenn Kuras]

of course i know the correct answer is just compress the 5.5 inch stuff as much as possible into about 3 inches and wrap it tight, hang 2 or 3 inches above the kit.

yea I think that is going to be your best bet.

Glenn

[avare]

the product has unusual absorption @125Hz when going from 3" to 5.5". I would NOT recommend compressing it for suspicion of increased internal reflection.

Andre

[RichS]

Use a kitchen electric carving knife, and let the blade cut at its own rate, don't force it. Also works great on soft or semi-ridged foam.

Use a large flat surface, place the knife on its side (might have to make some kind of jig to get the blade 2.25" above the table), and slowly slide the insulation through the blade -- like feeding wood on a table saw. Rotate the insulation to cut all sides... you'll probably have to cut the center by hand but it should be fairly easy.

Oh, and watch the fingers!

[falafel]

the product has unusual absorption @125Hz when going from 3" to 5.5". I "would NOT recommend compressing it for suspicion of increased internal reflection."

say that again? sounds like i will be cutting the stuff then.

andre, my bass traps are compressed to about 4 inches from 5.5 because i tend to wrap them pretty tight. what do you think?

...

RichS, the electric carving knife idea sounds nice. thanks!

makes me think of thanksgiving, and i don't even like turkey. mmm, cotton batt turkey.

[timothyallan]

Originally Posted by falafel

the product has unusual absorption @125Hz when going from 3" to 5.5". I "would NOT recommend compressing it for suspicion of increased internal reflection."

say that again? sounds like i will be cutting the stuff then.

andre, my bass traps are compressed to about 4 inches from 5.5 because i tend to wrap them pretty tight. what do you think?

...

RichS, the electric carving knife idea sounds nice. thanks!

makes me think of thanksgiving, and i don't even like turkey. mmm, cotton batt turkey.

I am literally taking a break from trying to cut 2" cotton tontine acoustisorb to write in this thread. I bought a turkey cutter thingy on advice from here... The turkey cutter idea worked great for 20 minutes until the blades dulled completely.

Then I went and bought some garden shears on a home hardware guys advice... no go... Then I did some more slutzing and found some guy who used a disc cutter/angle grinder with success.

Now I am off to home hardware again to buy their el cheapo disc cutter I saw on sale. Lets see how that goes!

[RichS]

Originally Posted by timothyallan

The turkey cutter idea worked great for 20 minutes until the blades dulled completely.

Those blades come apart and can be sharpened quite easily with a standard kitchen knife sharpener. Takes about 2 minutes to do.

[timothyallan]

I tried that once, but I honestly couldn't be buggered trying to sharpen them all the time.

I went and bought a $39 angle grinder and it was the best 40 bucks I ever spent. I'm doing corner triangles for superchunks and long straight cuts for big rectangle traps which == a massive amount of cuts. This grinder makes a 1.2m cut in about 3 seconds through the thickest Tontine cotton

[Driller]

As I mentioned on another thread, you want one of these with a metal cutting disc:



Cuts through cotton like butter. Wear goggles and watch your fingers!

[avare]

Originally Posted by falafel

andre, my bass traps are compressed to about 4 inches from 5.5 because i tend to wrap them pretty tight. what do you think?

With out test data, it is impossible to write anything accurate. From what I know of the product, it is worse low end absorption. I do not know how much. I do recommend doing that to anyone. You have done it, so live with it for the moment. If things are disappointing when installed make measurements and determine if the compression is contributing to the disappointment.

Andre

[Driller]

Originally Posted by timothyallan

I tried that once, but I honestly couldn't be buggered trying to sharpen them all the time.

I went and bought a $39 angle grinder and it was the best 40 bucks I ever spent. I'm doing corner triangles for superchunks and long straight cuts for big rectangle traps which == a massive amount of cuts. This grinder makes a 1.2m cut in about 3 seconds through the thickest Tontine cotton

Sorry Timothy, didn't see you'd posted that.

[falafel]

Originally Posted by avare

With out test data, it is impossible to write anything accurate. From what I know of the product, it is worse low end absorption. I do not know how much. I do recommend doing that to anyone. You have done it, so live with it for the moment. If things are disappointing when installed make measurements and determine if the compression is contributing to the disappointment.

Andre

oh okay, i will wrap them a bit looser for the remaining ones.