Can I use Schedule 80 PVC to make a ski boat silencer

J. Mark

Petty Officer 1st Class
Joined
Sep 3, 2008
Messages
303
While puting my boat back together I ran into a problem. The silencers are bad and have multiple leaks.

While I can order some primax silencers for about 120 dollars a piece, I was wondering if Schedule 80 PVC would work. I would need to fabricate baffles, but I think I can do that with a couple of pieces of stainless steel screwed in and counter sunk before gluing the fittings in place/ There might be another way to do it, but I was wondering if the Schedule 80 was usable-is it flammable or is there something else that would be a problem?

I couild build the same size and shape silencers in about an hour or two for about $50.00 or less and I wouldn't have to wait for the silencers.

Here are the primax silencers

http://bpi.ebasicpower.com/mm5/merc...oduct_Code=MUFMS-030-1000&Category_Code=ALL5A

any thoughts?
 

RotaryRacer

Lieutenant
Joined
Jul 18, 2004
Messages
1,361
Re: Can I use Schedule 80 PVC to make a ski boat silencer

I wouldn't do it. PVC is great for plumbing in your house. That is about it.

PVC is flammable. It also is not UV stable it will dry out and crack if exposed to sun. It is not very resistant to gas either. It also melts at a fairly low temperature.
 

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: Can I use Schedule 80 PVC to make a ski boat silencer

I believe it'll work . ?"pvc pipe is used in some houses for hot & cold water.
PVC solvent/cement will essentially make it one piece but I would test a cemented joint in a pan of hot water on the stove for a couple of hours for peace of mind.
Also, I would use a 60? elbow in place of the sharp angle of the Primex unit, for less restriction.

Edit, I've formed offset bends in pvc conduit after heating it on a bbq, so if your exhaust/water discharge is hotter than ~120? F, it will soften, possibly causing connections to the part to fail.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: Can I use Schedule 80 PVC to make a ski boat silencer

Bad idea. PVC softens when heated, a blow out will fill the boat with water and exhaust. Also it gives of poisonous gas when heated. If you want to make your own, look at buying stainless steel pipe and see what the prices are.
 

munch

Seaman Apprentice
Joined
Jun 3, 2008
Messages
30
Re: Can I use Schedule 80 PVC to make a ski boat silencer

You Can Use Pvc. But You Have To Get System 636. Normally Used In Venting Gas Fired Furnaces I'm Sure The Ratings
Are High Enough. But Check For Yourself. Ipex Makes The Stuff. Hope This Helps Don't Use Any Other Pvc It Will Burn And Cause Toxic Fumes. The Glue Will Have To Be Sytem 636 As Well.
 

J. Mark

Petty Officer 1st Class
Joined
Sep 3, 2008
Messages
303
Re: Can I use Schedule 80 PVC to make a ski boat silencer

Thanks, I just ordered the fiberglass ones-add two weeks to the launch date :(
 

drewpster

Commander
Joined
Oct 17, 2006
Messages
2,059
Re: Can I use Schedule 80 PVC to make a ski boat silencer

J. Mark i was wondering how much sound reduction silencer give you. I have an older boat that had no modern mufflers of any kind. LOUD MUCH? I was thinking about adding mufflers. Do they make a huge difference?
 

J. Mark

Petty Officer 1st Class
Joined
Sep 3, 2008
Messages
303
Re: Can I use Schedule 80 PVC to make a ski boat silencer

no, but they have baffles to slow water from coming in on stopping-I did consider just going with straight hardwall hose, but at 10 bucks a foot it isn't much of a savings.
 
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