flexible glue or solvent??

[Guest]

I have separated the rubber part from the metal part on my 850 intake manifolds. They were pretty loose anyway, whatever bonded them together is pretty much gone. I want to try to somehow re-attach the rubber to the metal. What type of flexible, gas/oil resistant glue would you suggest?
Yeh,yeh I know, I am going to buy new ones anyway, but want to try this first. Any suggestions??

 

[Guest]

Buy new ones:-D

 

[SqDancerLynn1]

They are history get new ones or you will forever be fighting problems with it not running right

 

[REDDY]

boots

boots

They are molded on with the rubber in a liquid state. I have wondered if you could heat the metal parts and slide the rubber on quickly. I also thought that perhaps there is a chemical that would melt the rubber. If yours are kaput it wouldn't hurt to try something. Maybe a chemist could help. :?

 

[jpaul]

New ones would be the best, but if you want to try a repair, use silicone sealant.

 

[mark]

Yeh,yeh I know, I am going to buy new ones anyway

Order them first. You can enjoy messing around with glues and sealants while they're on the way.

 

[t3rmin]

Silicone is generally broken down by gas, so I'm not sure silicone would be a good choice here. What about an epoxy? A good epoxy should be able to take the heat and the gas. Wouldn't be flexible though. Do you really need the bonding point to be flexible?

 

[bwringer]

New ones would be the best, but if you want to try a repair, use silicone sealant.

Won't work. Silicone sealant quickly turns to goo in the presence of gasoline and gasoline vapor, especially in a hot environment.

Throw them in the trash PRONTO before you do something stupid with them while the new ones are on the way. You're risking serious and expensive damage to your cylinder head.

I'm starting to sound like a broken record, but buy new ones and forget about the problem for another 20 years. ](*,)
(This also applies to petcocks, too.)

Other things that have been tried but do not work:
Silicone of any kind (yes, even the expensive stuff in fancy colors)
JB Weld
Epoxy (yes, even the expensive stuff)
Barge Cement
Rubber Cement
Seal-All
Stix-All
Mud
Spitballs
Elmer's Glue
Rubber Bands
Hoping or Wishing the Problem Would Go Away
Anger
Bargaining
Ignoring the Problem
Prayer
Masking Tape
Duct Tape (even Gorilla tape is powerless here...)
Spackle
Setting Idle to 2,500 rpm
Twiddling the Idle Mixture Screws
Washing the Bike
Armor-All
Soaking in Transmission Fluid

 

[Pearson]

Other things that have been tried but do not work:
Silicone of any kind (yes, even the expensive stuff in fancy colors)
JB Weld
Epoxy (yes, even the expensive stuff)
Barge Cement
Rubber Cement
Seal-All
Stix-All
Mud
Spitballs
Elmer's Glue
Rubber Bands
Hoping or Wishing the Problem Would Go Away
Anger
Bargaining
Ignoring the Problem
Prayer
Masking Tape
Duct Tape (even Gorilla tape is powerless here...)
Spackle
Setting Idle to 2,500 rpm
Twiddling the Idle Mixture Screws
Washing the Bike
Armor-All
Soaking in Transmission Fluid

That's too funny man. I've tried most of them but you've given me a few new ones.

 

[txironhead]

You left out bailing wire. ANYTHING can be fixed with bailing wire. At least according to my dad's mechanical theory......he had the shift linkage on his '63 Ford Falcon van wired together for three years before I could convince him to fix it right!

 

[pntrdave]

Hey Brian, I didn't see Bondo on your list, so maybe he could make a mold out of Bondo. Then borrow his wifes electric cooker to melt an old inner tube, and poor that into the mold. While it is still in a liquid form plunge the end of the carb into the molten rubber and hold it steady until it cools. :-D :-D Of course it would prolly be less expensive to just buy new, and the wife wouldn't divorce him.

 

[8trackmind]

Add Kittyhair as well. (Bondo with fiberglass strands)

 

[Guest]

Some good ones there!!!
But seriously, I'm just fooling around til the new ones arrive. So I decided to try the Permatex stuff I used on my crankcase halves. It's similar to Yamabond & is supposed to be solvent resistant yet have some flexibility.

 

[bwringer]

Ooh, forgot about the Bondo... of course, I could argue that it sort of falls under the epoxy category.

And how did I leave baling wire off the list?

 

[rustybronco]

silicone probably wont do, but if you must try
http://www.instantsolutions.loctite.com/stronger_Toughened.htm

 

[KEITH KRAUSE]

Please don't use glues/sealants to fix possible intake leaks. You'll just waste your time. Get new ones and new o-rings too if applicable.

 

[bwringer]

silicone probably wont do, but if you must try
http://www.instantsolutions.loctite.com/stronger_Toughened.htm

Nope. It's only good to 200 - 225 degrees. Plus, it's not flexible.

 

[Guest]

They are molded on with the rubber in a liquid state. I have wondered if you could heat the metal parts and slide the rubber on quickly. I also thought that perhaps there is a chemical that would melt the rubber. If yours are kaput it wouldn't hurt to try something. Maybe a chemist could help. :?

Before vulcanization (curing), rubber can indeed be softened, and sometimes melted, if it is done very carefully. After curing, the rubber can be slightly softened, but it can't be melted.

The rubber isn't liquid when it is attached to the metal. The formation of the rubber polymer from the rubber monomers is done in a liquid solution. The liquid is evaporated, leaving crumbs. The crumbs are washed, dried again, and compressed into blocks. The blocks are thrown into a Banbury mixer with carbon black (tires are 1/3 carbon black) oil, anti-oxidants and anti-ozonants and a bunch of other things, especially curing agents, and mixed until it is a stinking 300+F mass. The mass is milled into flat sheets and cooled. Often, this sheet is later forced through and extruder, which heats it again, and a small pieces are formed with particular shapes. Those shapes are put into a hot mold, next to the metal piece, which has likely been treated with a special glue. The rubber is subjected to severa; thousand psi of pressure as the mold closes. The entire thing heats up to somewhere near 400F while the curatives cross-link the rubber. After curing, the mold opens and the part is cured and inspected.

(I used to do this for a living. Who would have guessed?)

Get a new intake boot!

 

[sf-nathan]

I used a permatex type stuff that has been in my garage waiting for something like this. It was called "yamabond" and is a semidrying "liquid gasket". So far, since the spring, it has worked great.

But then buy new, for your sanity later.


Oh, I just noticed the post where you did use permatex. Hah, brilliant!

 

[argonsagas]

Before vulcanization (curing), rubber can indeed be softened, and sometimes melted, if it is done very carefully. After curing, the rubber can be slightly softened, but it can't be melted.

The rubber isn't liquid when it is attached to the metal. .

(I used to do this for a living. Who would have guessed?)

Get a new intake boot!

ASK AN EXPERT TIME



After reading this, it occurred to me that latex has a fairly high melt point, and is available in liquid form, so it could be painted on. The solvent, I believe, is ammonia and the solution mostly water. I have no idea how heat-stable it is once dried, but the paint-and-dry latex solution is used in making molds from existing items..