Silicon glue on the backplate - anybody

I hat having to cut those - I forgot how you call'em, thos things between the backplate ad the crankcase - and I came out with an easy way:

I just use the same silcon adhesive between the header and the exaust on piped engines.

I used it on my OS.32F and so far no problems.

Should I expect any kind of trouble? I figure that uif the stuff is good enough for header-exaust sealing it shoud also be good enough for the backplate.

Easiest way to go to replace a gasket.....should be fine.

>Easiest way to go to replace a gasket.....should be fine.

I also think it shouls wok fine, I just got suspicious because it's so easy...

Why is it not used by everybody?

Oh, thnks for reminding me the name "gasket"!

some people are purists I guess...

The main issue is CAN you get the backplate off when you want to, and how much are you going to "GOOBER IT UP" if you do manage. It's just not that hard to find an old postcard or piece of Manila envelope, cut a hole in it to fit the backplate, slap it on, punch some holes, bolt it on, and trim the outside with a #11 Xacto. There's better ways to save 3 minutes. Steve

>
>Why is it not used by everybody?
>
>Perhaps, when you have to take the backplate off, you will find out.
It all depends which type of silicon you used!

I've used the red high temperature silicone stuff sold by Permatex (IIRC) that's used for automotive gaskets. Seems to work OK, and you can get the backplate off OK.

>>
>>Why is it not used by everybody?
>>
>>Perhaps, when you have to take the backplate off, you will find out.
>It all depends which type of silicon you used!

Ron B.
F4Fguy

This is one of the few cases where you can have your cake and eat it too.If you do this carefully you end up with a reusable gasket.

(1)Remove the back plate.
(2)Thoroughly clean both the case and the backplate with solvent and allow to dry.
(3)Wipe a thin coat of oil on the case only,ensuring that all surfaces which will be in contact with the backplate are coated.
(4)put a narrow bead(about 1/16")of high temp silicone on the flange of the backplate,at the intersection with the"stuffer"barrel.
(5)Assemble the backplate to the case and tighten the bolts only enough to start to squeeze out some of the silicone.Be careful to keep an even thickness of silicone(thin is better than thick).
(6)Allow to set up overnight,then tighten the bolts evenly as in normal assembly.Excess silicone can be trimmed with an X-acto.

Done properly,the silicone will adhere to the backplate but not to the case,allowing several assembly/disassemblies before redoing the silicone.Also,don't oil both parts or the silicone won't stay in place when you tighten the bolts.
When you do have to redo the gasket,the old silicone can be removed with a soft wire brush.

I use this silicone at work ( the red RTV silicone )
I agree, it would make good gasket material.
But, why make any effort to re-use it ?
Myself, I would not try to do so, indeed I do not do so at work.
FYI I use it on a hot chamber that sits at 175 degrees Farenheit for 8 hours a day and the silicone lasts for years.
I also need it to make a good seal ( otherwise hot Ammonia vapour leaks into the work-place... NOT good.. )
It is cheap enough to make a new gasket every time you dismantle your engine and cleaning the "mating" surfaces will greatly reduce the risk of any leakage.

>I use this silicone at work ( the red RTV silicone )
>I agree, it would make good gasket material.
>But, why make any effort to re-use it ?
>Myself, I would not try to do so, indeed I do not do so at
>work.
>FYI I use it on a hot chamber that sits at 175 degrees
>Farenheit for 8 hours a day and the silicone lasts for
>years.
>I also need it to make a good seal ( otherwise hot Ammonia
>vapour leaks into the work-place... NOT good.. )
>It is cheap enough to make a new gasket every time you
>dismantle your engine and cleaning the "mating" surfaces
>will greatly reduce the risk of any leakage.
>
>Dave Moffitt

Dave; I agree with you basically,I was adressing the posts implying that dissassembly would be difficltult with the backplate glued on.
If you use the oil to act as s release agent,the realease is a snap.
Ppull the bolts and the give the backplate twist,and they'll usually slide right out.One of the advantages of this material is thah the gasket formed is an exact replicaof the two sursurfaces it is sealing.I wouldn't throw it away unless it was torn or fractured.

Ron B.

>
>:+

Ron B.
F4Fguy