Volvo trim tabs and Sound Down ?'s

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JohnCranston
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Volvo trim tabs and Sound Down ?'s

Post by JohnCranston »

Thanks in advance,
After a summer of being stuck on high center without anything getting done on Reel Cowboy, we're now in the finishing mode. Would you guys please advise on where to buy and what is reccomended when it comes to Sound Down and the Volvo Ql tabs?
Much thanks. We should be making some serious headway in short order.
I'll never ruin a $50 buzz with a $4 sandwich
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Mikey
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Post by Mikey »

John,
Glad you are finally in the "finishing mode." it only seems like forever.
Although Dreamsicle has been in the water for a year I am still working on her. planning on keeping her in the water this winter and completing the interior.
I tell people, who are dumb enough to ask, that I am eighty percent finished with about fifty percent to go.

On the Soundown you deal directly with a guy at the company named Steve Moyer. He lurks about this site fairly often. His number in FL is 954-761-9188. He is one of the Good Guys. Very helpful.
http://www.soundown.com/index_Marine.htm
Personally I used twice what he said would be sufficient and am glad I did as my Bride has tinnitis and the turbo whine on some boats made her nuts. Soundown all but eliminated it.
Don't know nothin' 'bout no tabs. Ain't gots.
Mikey
3/18/1963 - -31-327 factory hardtop express, the only one left.
The difference between genius and stupidity is that genius has its limits.
-Albert Einstein
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JohnCranston
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Post by JohnCranston »

Man, thanks. I rode on RenegadeMike's boat that had the Sound Down and it was extremely quiet compared to other Berts that I've been on. I've got to get some of that stuff.
I'll never ruin a $50 buzz with a $4 sandwich
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Rawleigh
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Post by Rawleigh »

John: Bruce can tell you more about those tabs, but Ii do know that the transom curve of the B31 requires that they have wedges put under them to keep them straight.
Rawleigh
1966 FBC 31
J Graham
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Post by J Graham »

Buce: Do you like the volvo tabs?
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Harry Babb
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Post by Harry Babb »

Hey John
We must be in the same mode.....I am installing Soundown also. I purchased mine from Steve Moyer just as Mikey suggested.

Steve suggested that I use the 1-1/2" thick @2 pound per square foot material. I paid just over $200.00 per sheet plus UPS charges......I think the sheets are about 40" by 60" (guessing)

Steve told me that high pitch sounds like Turbos whine are pretty easy to stop but the low pitch sounds that are emitted by our diesels require a very dense barrier to stop....hence the 2 pound.

I have talked to several others that have used the 1" material @ 1 pound per square foot and they are very happy with the results.

I will not be reporting the final results for some time to come.....but I am getting excited about the day when I hit the starters and NOT hear those puppys run.

Harry
hb
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JohnCranston
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Post by JohnCranston »

Harry,
That's what I was looking for. How many sheets did you buy? What all did you insulate? Thanks a bunch for the responses, everyone.
I'll never ruin a $50 buzz with a $4 sandwich
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Harry Babb
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Post by Harry Babb »

John
For starters I have the Express Cruiser.......I am insulating the outboard hull surface, the forward and aft bulkhead of the engine compartment, the undersides of the engine box and the panels that are on the inboard side of the engines. I purchased 6 sheets......hope its enough.

As per Capt Pat I am using 3M #90 spray adhesive to glue the panels to the walls and backing up the adhesive with SS screws and fender washers that are 1-1/2" Diameter.

The other choice of mechanical fasteners are the pins that glue to the surface.....in my opinion the pins are fairly expensive.....screws and fender washers are much less costly and very effective.

Harry
hb
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Bruce
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Post by Bruce »

Volvo Q tabs work well but do need a curved block under them. Not that hard to make either out of composite or use epoxy like creating a wedge for a strut.
that high pitch sounds like Turbos whine are pretty easy to stop but the low pitch sounds that are emitted by our diesels require a very dense barrier to stop
I have found in the application side that the opposite is true in most circumstances.

While lower frequencies do have higher sound pressure, its not the same as one of those ghetto cruisers bopping down the road blasting his twin bass tubes at 800 watts.

A good part of this can be attributed to how the engine is fastened to the stringers and how well the stringers are fastened to the hull structure.

When I build engine beds, carefull attention is paid to how after the initial grinding or build is done, how those stringer rails are fastened to the hull. In a Bertams case, factory 31 and 28 the top supports for the stringers are steel angle brackets with a couple of bolts. This has to go and make a more solid epoxy and glass connection.

Any loose tabing will allow vibration.

Next when the aluminum or steel cap is installed on top of the stringer, it is bedded into epoxy which will act as a sound transfer barrier.

When the mount risers are installed on top of the cap, a thin piece of composite material is placed between the two as another insulator.

Third carefull attention is paid to the mounts themselves. Some factory mounts will sag over time and bottom out. Throwing off alignment and tranfering noise to the risers.

All this is extra work but will make for a very quiet install.

Another area is make sure there is no contact with the stuffing box and shaft after final aglinment is done. This is where careful steup of bed and struts comes into play.

I've seen many boats have an otherwise good install go bad when trying to align.

If you have good size air boxes in the hull, chances are you'll get high pitched sound from these openings.

All installs I've done that have used sound down in the 31 have resulted in being able to stand between the engines at cruise and talk in a normal voice level.

Every single one of them though has never eliminated that turbo whine. While not piercing, its there and frankly offers a change from the gabbing jackass usually sitting next to me.

Besides the exhaust sound being used as a sync, its pitch also tells me engine rpm without having to look at the tachs and take my eye off the fast approaching path ahead.
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JohnCranston
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Post by JohnCranston »

Harry and Bruce,
Thanks again. Does someone know the model or size on the tabs?
Thanks.
I'll never ruin a $50 buzz with a $4 sandwich
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Mikey
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Post by Mikey »

John,
Harry and I have the same boats and I did exactly what he did. The only thing I haven't done (probably this winter) is to close the aft bulkhead around the shafts and insulate that. I used the glue and pin method on most pieces but the glue and screw on some. On the panels between the engines and the companionway I made those slightly over sized and they stay put. This gives me the advantage of being able to remove them easily to service the engines. I used Soundown's tape to finish the edges. Looks good and keeps crud out of the foam.
Mikey
3/18/1963 - -31-327 factory hardtop express, the only one left.
The difference between genius and stupidity is that genius has its limits.
-Albert Einstein
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Bruce
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Post by Bruce »

QL450 is the tab model.
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JohnCranston
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Post by JohnCranston »

Mikey,
How many sheets did you buy? and was it enough?
Thanks, Mikey.
Bruce, thank you again.
I'll never ruin a $50 buzz with a $4 sandwich
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Mikey
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Post by Mikey »

John,
Bought 5 sheets of 2" x 5' x 6'. Also bought 36 sq ft of acoustic foam to blanket the bilge. It came out perfect. Measured the area to be covered and figured out how many sheets by laying the pieces out on paper templates. Saved the templates and when the Soundown arrived used them to cut the sheets. Think that Soundown has an installation manual that explains all of this.
Mikey
3/18/1963 - -31-327 factory hardtop express, the only one left.
The difference between genius and stupidity is that genius has its limits.
-Albert Einstein
wmachovina
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Post by wmachovina »

John--I put Ql450s on Seachele. install was easy after a little epoxy/cabosil build up to flatten the transom curve. I'm a little disappointed in the performance of the tabs-little aft lift at all but they do control lateral trim well, which is really why I installed them. Also they dont garbage up the transom. Call my cell if you want. Bill 772 240 6146
Bill
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JohnCranston
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Post by JohnCranston »

Bill,
I'll give you a buzz tonight. Thanks.
I'll never ruin a $50 buzz with a $4 sandwich
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