I think I remember someone saying you can use a playing card to make a muffler gasket.

Does anyone have experience with this, or have another solution (that ISN'T liquid)?

Thanks.

Do you mean the space between the muffler and the exhaust port on the engine?

If so, why do you need a gasket?

The machined surfaced are usually fine for a metal-to-metal connection and a tight bolt.

CGr.

I have been using Silicon Adhesive Sealant purchased from AutoZone for many years. Wortks perfect.

Yeah...dont use one!

I couldnt keep the muffler gasket in my Super Tigre for nothin. I even tried other stuff. The instructor at our field told me to just not use one,as they never last long anyway. I took it out and everythings worked great ever since. I dont even think it leaks.

Not sure everyone would recommend this,but I know it can be done.

Wow, quick responses!

I need space so the muffler isn't resting on the side of the plane. The muffler extensions are much more than I need, and the holes on EVERY ONE are 1mm narrower than the holes on my muffler.

3 business cards is all the space I need.

If you just want a little bit of space, try cutting a thick gasket from sheet copper or aluminum. Most hardware stores have at least a small selection.

Those will burn away quite readily. Muffler gasket, available at your auto parts store may work, but the best solution is no gasket and the extension and put up with the gap.

CGr

The problem you will have with this is that this material isn't designed to be a spacer. It will quickly become saturated with fuel and exhaust residue and will either blow out and/or start leaking. You are going to come up with more problems than you are going to solve.

If this is still on the Nexstar you are building you really need to stop and figure out what is wrong with this plane. The Nexstars are a very well designed plane and if this engine doesn't fit correctly something is definitely wrong and should be addressed correctly, instead of trying to "rig it up".

Ken

The auto parts stores here don't sell bulk exhaust gasket, only ones for specific vehicles, which don't have enough solid material to cut one out of.

The exhaust extensions at Tower have 36mm between the center of the mounting holes, where the new 46AX has 37mm. Will this matter?

Being limited in experience with RC, I can't say how they'd perform long-term on a plane engine. However, I've used baseball card thickness cardboard home-made gaskets on cars and small engines since I was a kid, and it works fine.

Lay the cardboard on the contact surface. Take the handle of a screwdriver and tap the top of the cardboard all around the edge of the contact surface to mark the shape you want. Use scissors or a hobby knife to cut it out. Coat with gasket sealant and install. I've actually got a home-made muffler gasket on my OS 46 on my cub that I made this way. It has a good bit of run time on it without showing signs of burning away. Although, like someone else mentioned, I have no idea why you would need a gasket here in the first place. I just put one back on because one was there before.

I know this, but the thought of taking it all apart and shipping it back and starting all over again kills me. And this isn't a good reason but I've sunk so much extra money in parts (just bought the Hobbico spacer to solve my engine fitting problem) that it makes me just want to get it in the air. Actually when I called Hobbico about this the first thing they said was to cut away at the plane (this would have been 3.5 inches down the side of the plane) then they said to try the muffler extension (which I just broke down and did). Then they said to send it back. I've taken apart the front of the plane 3 times now and put it back together, meticulously following the directions and the advice and pics from everyone here. I know I didn't do anything wrong, but I did have to sand down parts of the nose gear, use a muffler extension, bend push rods around, etc. to get things to work. I really don't want to have spend another $20 on return shipping, then have all these parts laying around reminding me of the time that's been wasted if there really is something wrong with the plane.

you need to get a camera,for some of these questions.
this makes no sense, the muffler should clear the fuse if its so close you need to modify the engine that is designed to fit in the plane, theres something wrong.
if a couple of buisness cards will allow it to clear the fuse, then the heat of the muffler will burn the covering on the side of the fuse they get really hot.
hobbico will send a new plane to you, in the time its taken you to post all these questions about your troubles with this airframe, some ARF planes have problems,(the little person was working too long on there shift and got tired and made some mistakes)it happens,its gotten to the point where the signs are send it back and get a new one instead of fighting this thing.
as for ARF's if they don't just click together then they need to be returned,a small mod here or there sure, but this is a bit to much,my gut tells me this isn't a trustable airframe,and take some pics so you have documentation of these issues,the last thing Hobbico wants is some bummed out customer,they want you to come back and spend more money with them there in the fun buisness,for profit of course,but if its defective then it is.

One of these is not that wide ( or deep? ), and should do the trick for you...

[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD638&P=7]Click me![/link]

Of corse it's going to matter. The mounting holes has to match.
It'll be a snugg,snug fit and the screws won't line up good....so you taking a chance on
striping your muffuler's thread.

if it was me...I'd buy it becuase I'll just enlarge extension's mounting holes slightly with a drill
or a drimel.


I have rolls of aluminum tape...but it'll coast me more to send it to ya.lol
Or a roll of aluminum tape cost more than that extension

Yeah that's what I was thinking.

or cut some aluminum cans...but nuh,that might draw blood.

or use aluminum stock or metal plates ...such as window frames..or whatever.
A machine shop can do it i 5 mins..it'll take me an hour with a drimel.lol

Hmm. There's a machine shop at school, and I have a friend with a machine shop too. I got that Hobbico extender, let's see what happens. I'm going to call Hobbico (again) and ask their input on why I need an adapter to get a 46AX in a Nexstar.

I used cigarette boxes to make my own 40 sized engine muffler gaskets, they work fine, no leaks, I hate leaks! Just oil the mullfer side, make and imprint and cut.

They were never designed for gaskets. If you need more room, get the spacer that opjose suggests... or see what causes the problem you mentioned. I had the Nexstar and mine did not have any spacing problems at all.

Is this the one that you had problems with the engine mount? If so, perhaps you should have followed the instructions from where you bought it from and sent it back. This is beginning to sound like it's not going to make it past the maiden flight.

CGr.

My SuperTigre's 20 years ago all came with gaskets like you seek. And the mufflers just wouldn't stay on unless we used the red threadlocker stuff. (I'd use blue now)

And, like recommended previously I picked up a small sheet at an auto parts store and it was the same stuff.

You can also take the back of a legal pad, the thicker paper some call kraftkote and make a gasket from it. You could also cover it with a thin skin of RTV if you worry about saturation although I don't ever remember that as a problem... the gunk helps maintain the seal.

Heck, if it doesn't work out like you wish you can always go metal-to-metal.

Regards,

Clay

Allow me to correct my previous post. The OS's I own do not use a gasket. I have two .46's, one 50, two .75 AX's, three 1.20 AX's, and one 1.60 FX and none use an exhaust gasket. They do not leak, nor do they come loose if tightened sufficiently.

I also had a Super Tigre 75. That had different problems with the exhaust system. I won't go through that, but I eventually replaced the muffler with a MACS header and tuned pipe. And, I don't recall a gasket on that engine either and it neither leaked nor came loose on me.

CGr

Assuming your .46 is new,out of the box.....the owner's manual supplied reccomends high temp RTV (red) sealant between muffler and exhaust.It only takes a very small amount/ bead.I had some leakage between the muffler halves......RTV'd that part too.........no leaks now.

N1061D,
I'm not trying to start an aurgument here, but nowhere in the manual for the OS 46 AX does it say so use any kind to mount the muffler. Mufflers on OS engines are designed to be mounted with no gasket, and when installed properly they don't need one at all.

Ken

N1061D,
I was about to post that the manual didn't say anything about silicone sealant, but when I got to the manual page it did indeed say that they recommended it. I stand corrected and I thank you for showing me something I didn't know before. Guess that goes to show you, you learn something new every day.......... whether you want to or not!!!!

Thanks

Ken

I didn't know that either. Thanks for the update on that. I guess it goes to show that we really need to read the manuals a bit closer!!

But, one thing I CAN say is that my engines do not leak, even without the sealant. Now muffler halves, that's a different story, and we've talked about that in a previous thread.

CGr.