Soundproofing

[Jayson]

When I was in the military, I worked on a radar that had a heat exchanger on it. It was like a radiator for the transmitter section of the radar. I think to this day, I havnt heard anything louder except the jets that took off next to it. It was so loud that you had to have 2 forms of hearing protection to work near it.

This thing sat about 40-50 feet from my shop. If you were standing right outside the back door of the shop, you couldn't talk to someone standing next to you without almost yelling. All we did was put one piece of ply wood on the side of it that faced our shop, perpendicular to the fan. It made it 500 times better. It reduce the noise to a level that only required hearing protection if you were on the other side of the plywood or working directly on the heat exchanger.

I am guessing that if you put baffling on the ceiling and stood a barrier in front of the anvil that you should be good to hammer away. The barrier would reflect a lot of the noise back to your back walls and most would be absorbed by the baffling. Just a thought, and a really cheap one. Carpet makes for good baffling.

Also....there are different peins on hammers? Anyway, which way to the sword making forums? ;)

[Frosty]

Also....there are different peins on hammers? Anyway, which way to the sword making forums?

Oh yeah. . .

Thataway!

Frosty

[Tim tennis ball]

Hi, a first time post. I have got into anvil work, all cold work and I'm using a heavy chunk of forklift tine mounted on a big tree stump.

I trawled all the forums and established that I could deaden the ring by chaining down, with a layer of silicone caulk, plus I have a magnet on each end. These all help in deadening the ring. However on the soundproofing issues I may have something to chip in.

I am set up with a workshop in an old factory, which has heavy reinforced concrete floor, walls and ceilings. When I had the stump on the floor with a layer of thin rubber mat and silicone, and silicone plus the above mentioned measures between the stump and anvil, we still had an impact shock wave that travelled. So you had not the actual sound but a resonant sound that would travel through the heavy building and pop up everywhere. You could really feel the floor vibrate. And sounds could pop up 20 meters away.
A DJ friend suggested an old trick that was used for turntables in clubs, to stop the stylus skipping. They would use tennis balls, with a concrete slab on top, to make an vibration isolated platform.

I now have the anvil stump on top of a thick plywood board, that has a round recess in each corner underneath, in which a tennis ball is positioned. (NB Use pressureless tennis balls, as normal pressurized ones will just deflate over time). So theres well over 100kg on these 4 tennis balls. They are flatter but still there. I have little wooden blocks underneath with a tiny clearance, just for back up safety.
The impact vibration, hence sound, is gone to my perception. Standing next to it I feel no vibration through the floor.
There is obviously sound coming from the hammer blow, but none of the extra resonance.

Yes the anvil does wobble very slightly, and I know that would not be desirable normally. For what I'm doing (cold hammering annealed carbon steel for a certain musical instrument (the keys), it doesn't bother me.

Its a valuable example though, If you have the same problem of impact sound, there may be a similar way of adapting what I've done. I'm not sure that a thick rubber mat would have achieved the same result.

Also REVERB, increases the perceived volume of anything, because the sound is actually lengthened and layered. If I close my workshop door its loads quieter, even to me,, because if open the sound will reverberate through the corridor.. Avoiding plain bare walls helps too, breaking up sound reflections disperses the energy quickly.

OK, hopefully thats useful to someone at some point.