Papercrete as enclosure building material.

[dustman]

Has anyone considered the use of papercrete as a building material for speaker enclosures? Seems like it would be the perfect material since it has excellent damping, excellent strength to weight ratio and is extremely moldable and workable. Thinking it can be finished of with a coat of fiberglass resin on the outside to make a hard shell. The material itself could be painted or pigment could be added when mixing. Best of all the material (recycled paper) is free, plentiful and environmentally friendly.

[horst]

never heard of papercrete, but a quick search tells me it is paper and cement
umm
no

[Rick Lee]

Seems like it would be the perfect material since it has excellent damping,

Not to dampen your enthusiasm but cabinet resonance is not as much of an issue with horn enclosures as ported or sealed cabinets. Seems like more work for negligible returns. If you've used it before for other purposes tell us about it! Do you make it into panels first or just pour it in a mold?

[Rick Lee]

BTW, welcome to the forum!

[Charles Warwick]

It is generally used with a mold either to make shapes or bricks, so it would most likely not be cost and time effective for building these types of speakers since everyone would have to make a mold first and then make the speakers they need which is more work than just using wood.

Theoretically, papercrete could work, but logistically it'd be easier and more cost effective to just use wood.

You could always try it with a simple box to test it.

Best of all the material (recycled paper) is free, plentiful and environmentally friendly.

Well, it is better than some things but paper can already be recycled easily enough. Although it still contains cement which is a heavily processed material that requires a lot of energy to produce. Cement manufacturing accounts for approximately 7% to 8% of CO2 production globally, so it's not like it's free of emissions.

Plywood can be environmentally friendly, assuming that the forestry industry practices good harvesting and planting methods. One cubic metre of softwood plywood generates 80−150 kg of CO2 from forest to finished product. Additionally, plywood acts as a carbon reservoir which sequesters more carbon than is created in its production. One cubic metre of softwood plywood sequesters on average 800 kg of carbon, so the net result is a decrease in atmospheric CO2 so long as the plywood is in use and not destroyed.

See, we're being green.

[dustman]

Well, I'm gonna try it and see how it goes, I will post results, build time and maybe some pics.

The project is a ported box for 2 Dayton 10 " Classic woofers in the back of an Accord wagon. There will be recesses in the box to house 2 Sure Electronics amp boards, 1 for the "subs" and 1 for the 4 3" Tang Band Bamboo full range drivers crossed over at about 220hz, 1st order. Going to build 2 small sealed papercrete enclosures for the TB's, 2 per enclosure. All speakers will be flush mounted.

Rick, thanks for the welcome. In answer to your question I have used it before as a plaster, used it to make blocks to build a wall and helped another guy build panels which didn't turn out very well cause he didn't really know what he was doing, he used too small a proportion of cement and did not use a proper "mold" and they turned out warped and weak. I also experimented with papercrete with random mixes, compression (which adds an amazing amount of strength, but yields a heavier product that uses more material per size) and tried adding other materials to the mix to make it lighter or stronger or both. I am amazed by the workable, moldable, strong, and light nature of papercrete, it's a pleasure to work with. As far as getting a nice smooth appealing finish I'll see what i can do with this project. I am going to make 1-1/2" thick panels using a simple mold and put them together like one would do with wood. If I planned on producing many of the same enclosure I would build a mold that would shape the majority of the enclosure.

I think there is a lot more to the lumber industry than you are stating. Do your figures include transportation to the wholesalers, retailers and finally to the construction site. Lots of carbon there. They rarely have good practices, I have done too much traveling and seen so many forests absolutely devastated. Really there are no "good" practices because each old tree supports an astounding amount of life. Unfortunately a healthy old growth tree sequesters many times the carbon of a young tree. No offense to you, but they put out a lot of propaganda to make themselves look better in the public eye. There are many local sources for recycled paper and other binders can be used than cement.

Anyway, back to audio, thanks for the feedback!

[bzb]

It's funny to see a lot of these types of posts lately. Aluminum enclosures, papercrete, fiberglass... maybe someone will come in from the racing world and want some carbon fiber boxes.

I'd actually love to see someone actually post some build pictures of one of these "alternative material" cabs. I've seen finished products of some of the composites, but no ones posted really good build pics.

I'm into woodworking, so I have no qualms using plywood However, I could definitely see the hesitation of wanting to work with a material you're not familiar with (or have the tools for). I'd love to get into doing the composite stuff - just short on time to really learn and practice.

[Charles Warwick]

Well, I'm gonna try it and see how it goes, I will post results, build time and maybe some pics.

The project is a ported box for 2 Dayton 10 " Classic woofers in the back of an Accord wagon. There will be recesses in the box to house 2 Sure Electronics amp boards, 1 for the "subs" and 1 for the 4 3" Tang Band Bamboo full range drivers crossed over at about 220hz, 1st order. Going to build 2 small sealed papercrete enclosures for the TB's, 2 per enclosure. All speakers will be flush mounted.

Sounds like fun, make sure to post lots of pictures!

I think there is a lot more to the lumber industry than you are stating. Do your figures include transportation to the wholesalers, retailers and finally to the construction site. Lots of carbon there. They rarely have good practices, I have done too much traveling and seen so many forests absolutely devastated. Really there are no "good" practices because each old tree supports an astounding amount of life. Unfortunately a healthy old growth tree sequesters many times the carbon of a young tree. No offense to you, but they put out a lot of propaganda to make themselves look better in the public eye. There are many local sources for recycled paper and other binders can be used than cement.

Yeah, that's probably true, but the website claimed to include all the transport costs, but it was from a forestry company so take it with a grain of salt...

And I do agree that cutting down old growth lumber is a terrible idea, which is why sustainable forestry must rely on new trees and continual replanting and harvesting at a zero net loss of trees. But that's not exactly happening right now... But it has gotten better in the last 30 years... But I still maintain that from an idealistic view lumber is a better way to build than concrete because concrete requires processing, mining, and such, but lumber can be produced in a very sustainable manner.

But still, recycled paper is much better than nothing!

[Rick Lee]

I keep looking for Paulownia wood but have a hard time finding it. Supposedly very light- almost as light as balsa but incredibly strong. Can grow 30 feet in one season and when cut at the base will grow straight up again. Supposedly the lumber of the future for the U.S.

[dustman]

I keep looking for Paulownia wood but have a hard time finding it. Supposedly very light- almost as light as balsa but incredibly strong. Can grow 30 feet in one season and when cut at the base will grow straight up again. Supposedly the lumber of the future for the U.S.

If you find a source or have more info please let me know. Is it comparable in price to other common woods?

[Rick Lee]

Is it comparable in price to other common woods?

The articles I've read say it varies from $.50 bf to $7 a bf. For BFM use the articles say that it's just starting to be used in plywood. I have no idea where to find it- I'm assuming it would have a "name" like arauco or appleply.

[bzb]

I had to look that up, and I realized... we have thousands of those trees growing here in Atlanta. People plant them because they do grow extremely quick, and they have purple flowers that resemble wisteria.

They really do grow back if you lop them off at the trunk. Had a neighbor do that one year for some strange reason, and it still came back. He also cut his Bradford pears in a really strange fashion - looked like nubs off the main trunk - but now they actually look pretty good.

And wouldn't you know it:

http://www.worldpaulownia.com/html/paul ... house.html

Down there near Tifton, GA (where they grow a ton of onions). $12.25 a board foot though, ouch.

Too bad we can't use wisteria or kudzu. That shit grows 10 feet in a day.