RunRyder RC
WATCH
 7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ] 5304 views POST REPLY
HomeAircraftHelicopterMain Discussion › What is the best way to seal muffler
05-26-2015 05:58 AM  3 years agoPost 101
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

Maybe if you're burning gasoline, mineral or motor oil and can keep the exhaust really cool, then you'd have something
Too close for comfort, temp. wise.

And the OP was using a nitro 2-cycle, I think.

Epoxy is just not the correct way to solve this issue, it just seems the easiest....

PM  EMAIL  Attn:RR  Quote
05-26-2015 06:00 AM  3 years agoPost 102
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

Most of the Devcon over the counter ACE hardware Epoxy isn't good past 200F, and in particular does very poorly when up against alcohols, ketones, acids, alkalis. Maybe if you're burning gasoline, mineral or motor oil and can keep the exhaust really cool, then you'd have something!

Definitely not a product I'd consider here.
Doesn't look like 500 deg. F to me....and that's from the manufacturer...I'd prefer to use the recommendations that dk's link provided.

PM  EMAIL  Attn:RR  Quote
05-26-2015 01:10 PM  3 years agoPost 103
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

PC Epoxy (pcepoxy.com) has a putty called PC Fahrenheit, claims to work up to 500F. But also states temps above 360F will shorten life of the repair.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 01:49 PM  3 years agoPost 104
Jacoub

rrKey Veteran

Kuwait

My Posts: All  Forum  Topic

Can any nitro 2 strock heli engine reaches above 240F? specially mine 91srx?

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 01:58 PM  3 years agoPost 105
Mark Ryder

Administrator

Ann Arbor, Michigan

My Posts: All  Forum  Topic

I have found that the second you run hot (lean) then the seal breaks down.

Mark Ryder

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 02:05 PM  3 years agoPost 106
Jacoub

rrKey Veteran

Kuwait

My Posts: All  Forum  Topic

Can any nitro 2 strock heli engine reaches above 240F? specially mine 91srx?
I mean there is no need to take an epoxy that hold above 360F, As I know the max temp for synthatic oil is 280F, above that you will easily burn your engine

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 05:42 PM  3 years agoPost 107
GMPheli

rrElite Veteran

W. Bridgewater, MA USA

My Posts: All  Forum  Topic

Many people have used 5 min epoxy for many years without issues. Debate it all you want, but it works.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 05:46 PM  3 years agoPost 108
Aaron29

rrProfessor

USA

My Posts: All  Forum  Topic

For the guys using epoxy, when you go to take it apart, is it stuck on there real good? That'd be an indication that it didn't entirely melt away.

But it could also be that it gets warm and melts during operation, but has no where to go, so it reglues after cooling off. The only litmus test to see if that were happening would be to try to remove the muffler right after landing while the engine is still hot. If you had to pull on it in any way, it's sealing.

It's going to be difficult to determine if it's not melting/refreezing, because if nothing at all can make an ok seal, it isn't like a little wet epoxy will suddenly create a huge exhaust leak, right?

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 06:11 PM  3 years agoPost 109
Jacoub

rrKey Veteran

Kuwait

My Posts: All  Forum  Topic

Watch at YouTube

look at min 5 and after

PM  EMAIL  GALLERY  Attn:RR  Quote
05-26-2015 06:18 PM  3 years agoPost 110
Aaron29

rrProfessor

USA

My Posts: All  Forum  Topic

Yeah so high temp epoxy.

PM  EMAIL  GALLERY  Attn:RR  Quote
05-27-2015 06:38 PM  3 years agoPost 111
HeliRyan

rrApprentice

Colusa ca

My Posts: All  Forum  Topic

Sealing exhaust

You're welcome

I don't crash, I land at full speed!

PM  EMAIL  GALLERY  Attn:RR  Quote
05-27-2015 06:44 PM  3 years agoPost 112
Jacoub

rrKey Veteran

Kuwait

My Posts: All  Forum  Topic

PM  EMAIL  GALLERY  Attn:RR  Quote
05-28-2015 01:21 AM  3 years agoPost 113
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

Sealing exhaust
From their website:

"Temperatures extremes of 350°F (176°C) to 500°F (260°C) will reduce service life of the repair."

PM  EMAIL  Attn:RR  Quote
06-01-2015 07:43 PM  3 years agoPost 114
said

rrNovice

Cape Town

My Posts: All  Forum  Topic

In the automotive industry we (South Africa) have a product called fire gum its used to seal manifolds on motor vehicle engines. I tend to put a very fine layer between engine and exhaust and tighten bolts the normal route where i cold tighten and then again when engine has reached operating temp. I Googled the product see link http://www.amazon.co.uk/HOLTS-EXHAU...E/dp/B0055OQRP8

PM  EMAIL  Attn:RR  Quote
06-07-2015 02:49 PM  3 years agoPost 115
ssrobzoom

rrKey Veteran

Tn

My Posts: All  Forum  Topic

I have been flying nitro Helis since 2005
Never had one issue with JB weld no leaks no mufflers vibrating loose

Clean both surfaces with lighter fluid then run a thin layer on the surface of only one surface and mate the two and allow to dry I usually use JB Kwik which is five minute set time.
Disassembly is easy too when needed.

You can usually fine this at all major hardware stores Lowes, Home Depot etc.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-07-2015 06:26 PM  3 years agoPost 116
raholek

rrVeteran

Zachary, Louisiana

My Posts: All  Forum  Topic

Arguing sealing systems
SO the OP doesn't jump down my throat.
I am an apprenticed machinist who moved to machinery reliability and hold licenses in signal analysis of rotating equipment. My former job (17 yrs ago) was a mechanic/machinist in a High pressure (1500-45,000psi) compressor plant. So ...just in case you want to discount my experience.

Many guys (Sponsored pilots-seems their opinion carries more weight) in our area use 20 min epoxy and the like to seal their mufflers. I tried it. Killed and OS 105 and had to wack the muffler with a rubber mallet to remove it. Failure was no fault of the exhaust seal.

The joint between motor and exhaust should never see the temperatures required to degrade that epoxy. As pointed out before...oils start to go away at ~260 F depending on type. But that is a good benchmark. If you see temps near that you will be worried about the cost of new engine parts, rather than a little exhaust leak.
Also the method of flattening the metal and using the torque of the bolts is a preferred method by most machinery types(metal/metal). Gaskets can shrink, move around and/or degrade over time. Our company uses the metal/metal joint for all high pressure applications. We even uses metal gaskets that compress very tiny amounts under torque.
We Also use a type of gasketless seal(ie: mechanical seals) to seal gases on our rotating equipment. Just requires flatness in a low light-band range to seal the gases. And a little higher pressure on the outside and/or spring pressure to seal up. These seals are actually monitored by our government.

OP: Good luck with your quest for a perfect seal. But sometimes GOOD Enough is perfect for a job. And time seeking perfection is just wasted time.

By the way...after your Tirade at a few guys who posted perfectly good information. I have no idea why anyone is still trying to offer you advice.

www.redstickrc.net ama#: 968515

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
06-07-2015 11:09 PM  3 years agoPost 117
basmntdweller

rrKey Veteran

Indianapolis IN

My Posts: All  Forum  Topic

Pretty comical IMO all this argument over sealing a muffler on a YS. My only concern is keeping the muffler on. The perfect seal is irrelevant. I have used a number of different mufflers on my YS' some with pressure nipples some without. I have plugged them on some other times left them open. The engines don't run any different with a little leaking. FWIW, I've used about every method mentioned but have given to just bolting it on and retorquing after flying.

Matt


Stupid people have no idea how stupid they are!!!

PM  EMAIL  GALLERY  Attn:RR  Quote
06-08-2015 01:32 AM  3 years agoPost 118
Aaron29

rrProfessor

USA

My Posts: All  Forum  Topic

You'll find that any thread that's long will have drama.

PM  EMAIL  GALLERY  Attn:RR  Quote
06-08-2015 07:14 AM  3 years agoPost 119
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

will have drama
Just have to be patient...and wait, ku that is....

PM  EMAIL  Attn:RR  Quote
09-02-2015 10:14 PM  35 months agoPost 120
Andy from Sandy

rrElite Veteran

Bedfordshire, UK

My Posts: All  Forum  Topic

The main thing you're missing is you must retighten after they are hot and have expanded. And then they will not come loose.
I do this but the expansion of the alloy is greater than the bolts so in theory it doesn't make a lot of sense.

It would make more sense to heat the bolts only to a higher temperature than when the engine is running so they pull the muffler on tight as they cool down.

On the relatively soft alloy I would think a 220 grade paper is far too course. Someone suggested 1200 and I find that works to prepare the mating surfaces also.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ] 5304 views POST REPLY
HomeAircraftHelicopterMain Discussion › What is the best way to seal muffler
 Print TOPIC  Make Suggestion 

 14  Topic Subscribe

Saturday, July 21 - 8:59 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online