Great News For Those Who Need Acoustic Panels & Bass Tra

I just got 36 Jonh's Manville 2'x4'x2" panels (192 sq. ft) and paid ONLY $215 ! That will yield me: - 7 (floor to ceiling) bass traps - 16 wall-hung panels. Control Room: - 4 traps - 10 wall-hung panels Drum/live Room: - 3 traps (one corner is an open closet) - 6 wall-hung panels Got it from S.P.I. (Specialty Products & Insulation) over here in Oaks (Philly area) Pennsylvania. Drove one hour, and picked it up myself. They have locations all over the country, so check 'em out. John's Manville acoustic panels are almost (if not exactly) the same as 703. So treat 2 of rooms to a full acoustic "spa-treatment" - all for around 2 hundy!

good info Brad - yes it's the same as 703 as is Roxul AFB. cheers john

pix ;) (damn, I keep repeating myself.. sorry)

Here ya go. Correction: either the sales person gave me this insulation at $.70 a sq ft, or he made a mistake. I ordered 192 sq ft, paid for it ($215) but got 288 sq ft. 4 packs. 1 pack = 9 panels. So, something weird going on. May be the studio-building Gods looked down on me. I'm guessing everyone gets "some" kind of a break while doing their builds. :wink:

John Sayers wrote:

good info Brad - yes it's the same as 703 as is Roxul AFB. cheers john

Maybe we can make this a stickie? I'm guessing that almost everyone (newbies and old timers) are under the immpression that 703 is THEE thing they NEED. I know I always thought so. After reading the stickie on building "Super-Chunk" bass traps, I saw that the builder used Johns Manville. That's what made me investigate. By way of comparison: If I were to buy 192 square feet of Owens Corning 703 from eBay, at around $80 for 6 panels and around $25 for shipping, I would have paid $420 in total. For my lot of Johns Manville, I paid half! This means a tremendous savings for someone doing a large-scale build! Hope this helps.

Or post a link in the "builing product" forum http://www.johnlsayers.com/phpBB2/viewforum.php?f=6

BradJacob wrote:

John Sayers wrote:

good info Brad - yes it's the same as 703 as is Roxul AFB. cheers john

I'm guessing that almost everyone (newbies and old timers) are under the immpression that 703 is THEE thing they NEED. After reading the stickie on building "Super-Chunk" bass traps, I saw that the builder used Johns Manville. That's what made me investigate. By way of comparison: If I were to buy 192 square feet of Owens Corning 703 from eBay, at around $80 for 6 panels and around $25 for shipping, I would have paid $420 in total. For my lot of Johns Manville, I paid half! This means a tremendous savings for someone doing a large-scale build! Hope this helps.

This comes up semi-regularly. Yes it is well known amongst the experienced designers/builders. My generic response is

Use whatever is the cheapest and fits what you need. 703 generically is "3.0 lb/ft^3 fiberglass". Roughly speaking acousitcally the Rockwool equivalent generically is "4.0 lb/ft^3 mineral wool" Just some of the companies that have similar productrs are: JM Roxul Knauf Delta Fibrex

and

In my neck of the woods Roxul safe n Sound is the price bargain being about one third 703 in similar thickness. The Safe N Sound is 3.5" thick, but the absorption is comparable to 703. Call your local commercial insulation companies and ask.

Andre

Andre Good post. Link to your other related topic: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=9677 And Bob's good absorption page: http://www.bobgolds.com/AbsorptionCoefficients.htm It's good that you enter Bob's link in your own topic as well.

Thanks Eric. I was going include a link to Bob's excellent site. I decided against it at the time, trying to keep the response easy to read for new people. You got it. It sould be easier for new people having little posts to read, as opposed longer ones with much information, although I do write those also. :lol: Andre

Andre, It's not even for the detailed content. Just glancing at Bob's page makes clear that 703 is no "Standard" but only one of countless options, which is what you rightfully wants to make clear. And only if they want to know more they can search that page. You see this thread. BradJacob is rightfully proud that he found a cheaper alternative for THE 703. You rightly put THE 703, and alternatives in context. Bob's page shows there are, as a matter of speech, hundreds, and the 703 is only an alternative among many, not THE standard, against which the others need to be weighted. :) Warm regards Canadian ..

I love that stuff I made my first ten panels with it. Its looks good with the cloth on it and easy to cut with a circular saw. Way cool 8)

Phunkeman wrote:

.. and easy to cut with a circular saw. Way cool 8)

:shock: Circular saw, isn't that a bit much? :shock:

Nope its straight and clean and quick and easy. Sounds like a commercial :lol:

Phunkeman wrote:

Nope its straight and clean and quick and easy. Sounds like a commercial :lol:

In as far as useful: At least here Rockwool is cut with a knife. They give such huge knife for free to (very?) good or industrial customers (has a large Rockwool name on it). Must be dusty stuff using such a circular saw and heavy to work with when sawing thick boards (diameter saw).

Those electric bread knives work well for cutting insulation.

Well my first set I made I was making the frames tight by about 1/8 of an inch. I remember after making one I made one frame too small and it didn't fit the panel. So I had to slice a bit of it off. After mucking up the panel trying to cut it I had to salvage it and grabbed the circular saw and it sliced a 1/2 inch smooth like wood. Thats why I said that. I'm sure your other methods work fine. Its just quick and gives a smooth edge. Recently I was making some clouds for my place and had to use semi ridgid rockwool/mineral wool (8pcf) and it cuts clean the same way. If you have a lot to cut it will make short work of it. Try it on a piece. Now I don't know off hand what kind of blade is on my saw probably something that leaves a small kerf. I don't know, but I will go outside and look and get back to you guys if your interested. What can it hurt.

It is a finishing blade.

John Sayers wrote:

Those electric bread knives work well for cutting insulation.

I know John, used them also. I just put my post as opposed to a circular saw (overkill, dusty and not safe since wool not really stable). For most boards a good knife works faster, but for a DIYer electric bread knives give easy to control cuts. I worked for an international company with several thousand people industrial isolating on a daily basis with mineral wool on a continuous basis (that means buying mineral wool of several types/brands with truckloads), and they used 2 tools in the field: 1) such knives for boards: http://www.clearskymedia.co.uk/insulati ... ckwool.htm http://www.rockwool.ee/sw42051.asp (there are different types hence don't look all the same) If these electric bread knives should be faster (costing little bought in mass versus cost man hours) they should use them or design more adapted versions. Mineral wool is produced and used with hardly imaginable quantities a day. 2) and these large manual "Hedge shears" for these chicken wire blankets: http://www.orchardsedge.com/tools.jsp?type=hedgeshears 3) And for foam we used either a knife or this Bosch foam cutter: http://www.perfectfit.com/product.asp?P ... 2&l2=15374 It's the same principle as such an electric bread knive, but the guide rolls on small minni rollers and it's finer, much sharper and complete different quality. It easily allows to make nice straight cuts. But's it's not as cheap as bread knives, far from. You don't find the latter easy in stock in tool shops dealing the Bosch products (since too specific), but they all can order it (at least here, but I assume anywhere). I think not many know the existence of this Bosch tool.

The other night a guy won "The New Inventors" with chain saw using the bread knife method. http://www.abc.net.au/tv/newinventors/txt/s2063371.htm you can cut into soil with no bad effects as it doesn't use oil for the chain.

John Sayers wrote:

The other night a guy won "The New Inventors" with chain saw using the bread knife method.

:) Heee, that's fun. Looks as a very good and inventive tool.

Phunkeman wrote:

Now I don't know off hand what kind of blade is on my saw probably something that leaves a small kerf. I don't know, but I will go outside and look and get back to you guys if your interested. What can it hurt.

Some things: 1) It isn't safe and I doubt any safety engineer should allow this method with a hand circular saw. 2) It's complete overkill. That industrial isolators, with quantities thousand times larger than yours, use a knife is not because they can't afford an electric circular hand saw. 3) That safety thing over your saw blade, is designed to encounter hard, sturdy materials, not soft boards. I can imagine that it can easily stuck into the soft board if not doing it carefully. 4) To get through thick boards the saw blade diameter becomes too large needing a large and heavy type of tool, making it unpractical to control on flexible boards and even more dangerous. 5) It's bad for the tool itself, if used a lot. Mineral wool dust/particles (whether fiberglass or rockwool) is as grinding powder/particles (made from hard volcanic rock, e.g. diabase or basalt, or sand). The tool has to be protected against it, or you must suck the dust away with a vacuum system. And with the width of the blade teeth you convert a lot of mineral wool into dust. Which is also why (among some other things) a lot of foam is still used for absorption in relative narrow industrial enclosures where absorption is used. Your tool or motor sucks in this grinding powder/particles for its ventilation/cooling. And you can hardly compare a motor and value of a good circular saw with one of an electric bread knife, creating much less dust to begin with, since it works as scissors. 6) If you made a small mis cut needing to further cut only few mm away then the bread knife as suggested by John is the perfect answer. And if you feel more comfortable with such an electric knife than a standard good knife, you can use it for all cutting work.

It ain't that big of a deal. A corrective cut only when I muck something up. Its quick and that old saw is mean.

A typical blade is 24 tooth framing...thats prolly a 60 carbide tooth blade. Now that is overkill! And use a dust mask. You people make me nervous with all that zeal...

Wow dudes that blade was on the saw when I grabbed it. I think I was making a quiet box or something before. You guys are cracking me up. I'm in the garage and didn't have one of those knives and I'm not going in the house and getting one of those bread cutting knives. Look up and see the saw and say "what the heck" and used it. I was surprised it cut soo smooth on such a small piece. Thats all. Yea dust mask and gloves are a must. For sure. I hate this stuff to get on me. 10 seconds I'm done. The overkill info on overkill was great. Thanks

If you cut me with a 60 tooth saw blade it would be smooth too!