Salem Oregon conference center studio

[Guit-picker]

My project partner will be building up the hanger panels. He has the idea to mount each section of hangers by "stringing" them across horizontal bars like this:

Temp1_hangars.jpg

I have been figuring something more like this, using zip ties (which are very strong and adjustable), which would allow them to freely swing like this:

Temp2_hangars.jpg

My concern is that the first method may hinder the panel's function, being to "stiffly" mounted. What do you think? Am I right?

-Ron

[Guit-picker]

I have mounted the first of three sections of the rear hemholtz resonator / bass trap in the rear: This is the ugly side up, when I couldn't flip it over (~250 lbs) without the help of four 20-year-old volunteers:

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We hauled it into the control room and got it installed. I'm pretty jazzed:

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I am almost done with section two. I am still in a quandary over what exactly should go behind it for insulation before I can install the 3rd section. There seems to be no consensus in our discussions. Can I get some help deciding the right thing?

Also, some input on my last post is needed about hanging methods before my project partner starts up building them. I don't want him to go off in the wrong direction.

I'm getting into some really interesting phases now and things are stepping up in speed. I have more time lately to work on the studio since my job hours are reduced, due to the virus issue.
Stay safe and healthy out there!
-Ron

[Paulus87]

I would use zip ties to hang the hangers, this method was recommended to me by John and it’s how I did it, ended up working well.

Paul

[Gregwor]

Ron,

Three things:

1. I love your signature.

2. You should be jazzed about the resonator. It looks unbloody real!

3. Zip ties would be better than the other method.

Greg

[Guit-picker]

Yo, thanks you guys! I feel assured now!
So thankful for this forum!

What about insulating inside the bass trap? I have heard three ways:
1. Fill it up with Roxul
2. Line the back with Roxul and put a thin layer of fiberglass along the rear of the timber
3. Just throw the out cuts of Roxul in there (Not sure if that meant fill it up or what).

-Ron

[Paulus87]

Yo, thanks you guys! I feel assured now!
So thankful for this forum!

What about insulating inside the bass trap? I have heard three ways:
1. Fill it up with Roxul
2. Line the back with Roxul and put a thin layer of fiberglass along the rear of the timber
3. Just throw the out cuts of Roxul in there (Not sure if that meant fill it up or what).

-Ron

If it was me, I’d cover the walls, floor and ceiling behind and then loosely fill the cavity with low density fibreglass.

Paul

[Guit-picker]

Thanks Paul!

Well, as of last night, section two of three has been installed..... after re-assembling about 3 times to get it right. It will be a while until the 3rd section goes in. I have to insulate and then start from raw materials on the lumber. I had to wait to see what the remaining heights and widths would be (because of tolerances adding and slanted top, etc) before I could start cutting out the lumber and veneer and such:

20200329_192358.jpg

-Ron

[Gregwor]

If it was me, I’d cover the walls, floor and ceiling behind and then loosely fill the cavity with low density fibreglass.

I wonder how hangers back there would do

It will be a while until the 3rd section goes in. I have to insulate and then start from raw materials on the lumber. I had to wait to see what the remaining heights and widths would be (because of tolerances adding and slanted top, etc) before I could start cutting out the lumber and veneer and such:

Ron, it looks so good. Are you able to take a nice close up picture for us to see the finish? Also, did you joint any of the lumber to get a nice straight look?

Greg

[Guit-picker]

Thanks Greg!

Are you able to take a nice close up picture for us to see the finish? Also, did you joint any of the lumber to get a nice straight look?

I have been away from the project for about 3 days - between work and just had a team of guys replace ALL my windows and patio door to the tune of $35,000 (the good stuff).

I did not joint any of the lumber. I had a tough time finding decent lumber and bought the straightest and driest I could find. I had to pick through it, looking for straightness and a good edge to support veneer. Ironically, the kiln-dried that I COULD find was worse than the rest! That being said, I had to deal with some warping effects. I used spacers to help line them up and a lot of screws and clamps in the process.

I will take a close up of the birch surface next time out there - possibly tomorrow. As I build the last section in the next week or two, I will try to snap more pics and share kind-of a step-by-step of the method used.

This isolation thing with the Covid-19 has allowed me more time in some areas and in others it's been a hindrance, being isolated and working alone.

Be careful - stay healthy!
-Ron

[Guit-picker]

As promised, here is a closeup of the wood veneer finish on the rear Helmholtz / bass trap. I made the resolution as high as I dare go, according to forum rules:

20200405_160327_001.jpg

I cut the lumber to size for the last third of the trap. I am now prepping for the addition of the veneer. I had to order an additional 4/8 sheet of birch veneer to finish. When it came, it looks quite different. It has much more figure and a bit darker . That means that four of the pieces will look different than the others. I hope it doesn't stick out like a sore thumb. I wish the first veneer looked like the new!
-Ron

[Gregwor]

Wow. That looks unreal. I've never used veneer before. I'm scared but I've watched a lot of videos about doing it. Care to document your process for the last module?

Thanks!

Greg

[Guit-picker]

I'm scared but I've watched a lot of videos about doing it. Care to document your process for the last module?

Yes, I am planning on a step-by-step documentation. I worked on it the last two evenings and am taking photos. I will post soon. I have the 3rd and last section veneered as of tonight. Next comes a little trimming, then light sanding then 3 coats of finish, then assembly and installation.
It's not hard, but I will share a few things to watch for. (I used to repair antiques in a refinishing shop many years ago while going to college for electronics.)

Today I also managed to get most of the insulating behind the trap done before I ran out of fiberglass R30 insulation. It is nearly to the ceiling now. Here are a couple of photos detailing what I ended up deciding to do:

20200410_171922.jpg

20200410_171855.jpg

-Ron

[Guit-picker]

The bass trap is installed completely now (except trim). So glad!!!

20200503_210647.jpg

[Guit-picker]

I want to be a “man of my word” by fulfilling the promise I made to Greg to explain the process of veneering and a little bit about the bass trap, in hopes that it could be of help to others. I hope this isn’t too elaborate!
After picking 2x lumber for straightness and rounded edges, I start by picking the best edge for the front that will be veneered. To make sure it would have a good corner for bending veneer around, I routed the edge to a 3/16” radius. If I had it to do again, I would go with ¼” radius. Rolling the birch veneer over the 3/16” edge was pushing it a little bit too tight and I got a few spots that were trying to split.

20200405_195801.jpg

I cut a whole bunch of ¼” spacers and spray painted the edges with flat black so they wouldn’t be visible inside the Hemholtz slots. Then cut each board to length and painted the sides black. The idea is that I didn’t want the end of the veneer to show in the slot and black has a way of making it “invisible”.

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I used 2 ½ sheets of birch veneer in this bass trap (4’ x 8’ sheets). I calculated the widths of the veneer strips to allow 1” depth penetration into the slats and ½” penetration between boards with no slats. This meant I had to cut two widths: 3” and 5” because some boards are offset by 2" deep.

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I drew center lines on the edge of each board and a corresponding alignment line on each strip of veneer, so the overlap would come out right. Also, I marked and taped off the areas on each board where the contact cement would go. I trained my young assistant to glue a few boards and veneer strips at a time (while promising his parents to be practicing social distancing and taking COVID-19 precautions). Make sure a medium-thick layer of glue is applied. The boards and the veneer can absorb the glue and it can get too dry. If that happens, you may have veneer coming loose later and will have pains trying to repair it.

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I carefully labeled each board and strip pair and kept track. The overlap is different from piece to piece and it gets confusing to keep track. Give the contact adhesive about 20 to 30 minutes to dry to the point that it is pretty tacky/dry.

When placing the veneer, it is important to get it right the first time, since the contact cement isn’t very forgiving and wants to stick immediately (of course). Back in the day, I used to lay out a bunch of dowels across a glued up table top and carefully placed the veneer sheet on the dowels. Then I could align the veneer up and start pressing it down from the middle working outward while pulling the dowels away. In this project, I have board EDGES – a bit different. After scrounging around for a method, I found a big coil of #4 insulated wire and cut a whole bunch of pieces and shaped them to go over the edge and placed them like this (the board is glued and ready):

20200410_192437.jpg

Then, with help from my assistant, we laid the strip over the board and lined up the alignment marks:

20200410_192549.jpg

Starting from the middle, working toward the ends, I press the veneer down on the edge while sliding the green wire spacers aside until the whole strip is down (while my assistant is keeping his end in alignment). The next step is to take a piece of 2x4 block with a “friendly” rounded edge and press firmly up and down the veneer with a lot of weight to get it firmly tacked down. Then carefully start forming it around the edge to the sides with the block, almost like ironing. Put a lot of good pressure to make sure it’s tacked down. Next, trim the ends with a razor knife and sand the trimmed ends slightly to make them round and smooth, so they don’t “catch” and tear.

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Briefly sand the veneer with an orbital sander and then block sand by hand. Be brief, because it is easy to sand right through the veneer. Sanding makes all the difference in the world to the look of the finish later. It brings out the beauty of the grain. I learned that working in a furniture refinishing shop.
I finished by brushing with 3 coats of oil based spar urethane in this case because it turns a little yellow. I wanted the “golden” color that looks good on birch. Sand between coats with 400 grit and wipe down with a tack cloth. It really helps to smooth out the finish that way.
After that came the task to assemble each of three sections, dealing with a bit of warps and twists and tolerances that would add up as I assembled 40 boards from left to right.
Here is a partially-assembled section. By the third section, I was getting the hang of it!

20200418_175643.jpg

[Gregwor]

This is so valuable. Thank you so much!!!

Greg