Marine-Tex Epoxy?

[DKWRACER]

Hello Poggers, am about to set some steering races into the frame headstay. In previous posts, there was mention of a super epoxy as mentioned. ?, in looking at their products, they offer a two part rapid set in 2 oz. (like JBWeld) or another "industrial" grade in 2 oz..any experience/advice greatly appreciated []
Thanks in advance, Tom.........

[Rain Man]

Hi Tom,  I always thought the steering head races were a pressed in fit.  Which means drifting them in with a hammer and punch ?? (preferably brass)
  I'm not sure about JB weld or other epoxies, Unless the race slips right in without the drifting procedure.
  All and all, I'd think that once you load the bearings with the steering crown adjusting nut... nothing would move but the ball bearings, preferably.

Raymond
 Down East Pentons

[454MRW]

The three set of steering head bearing races that I have installed so far (1977 & 78 MC5's) have required freezing the races before installation because the fit was so tight. I always use a little red Loctite as a bit of extra insurance on the race prior to installation with the flat end of a large socket used to drive the race into place cautiously with a large hammer. Mike

Michael R. Winter
1974 250 HS-1980 250

[t20sl]

Tom:  I have seen frames where the races were loose due to having turned or frame hit fairly hard and pocket went egg shaped.  I have used a standard Devon Epoxy of the 15 minute set variety.  $ minute would work also but usually has slightly lower strenght.  Usually 15 min has about a 2,500 to 3,ooo PSI tensil strength.  Rough up the outside of the race and the inside of frame pocket with some 220 to 320 grit sandpaper so it gets a good bite.  Clean with contact cleaner or acetone etc. Had to remove a race that was put in that way several years later and epoxy was still holding it great. Ted

[DKWRACER]

Ted, thanks for sharing you're thoughts on the steering races. This was a problem on early CMF frames and hence came a change to later frames that had a round gusset support. Will be prepping as per your suggestions, but am trying the Super Epoxy which was mentioned in previous posts, Thanks again, Tom Brosius. Oh, BTW, went shopping for the rubber o-rings to seal the bearings.....Buna type was not recommended by our local vendor, went with EPR or ERP type at .65 ea.....could have also purchased Viton orings at 6.00 + ea. imagine that!
Thanks, Tom Brosius

[john durrill]

Tom ,
 We used JB weld on one bike. It is still holding. You might try useing a center punch on the cup's in the frame to tight up the fit. A random pattern should do it. Then Epoxy it. Thats what we did 2 years ago and it is still holding.
John D.

[DKWRACER]

I will "coin" thee......Father John, from my typesetting days.
Trivia......what is a "coin" really......Tom....

[wildman]

3M makes an industrial epoxy that is rated at 190,000psi, called 3M Scotchweld DP-190. It comes in a double tube syringe type dispenser that uses a special gun to squeeze it. A disposable nozzle with a internal mixing device can be used. Can't remember the exact price but it was reasonable, like $10-15. My local distributor loaned me the gun free to use for a day or two. I have also simply pushed some out with a rod and mixed it manually. I used this on some loose steering head bearing races on my Penton racebike with so-far complete success. I  used a sandblaster to clean the frame pockets and back of the races first, then cleaned with acetone. I took a piece of 1/2" threaded rod and proper sized flat washers through the steering head and clamped the races together while the epoxy set up. It's held for 3 years now.
BTW, the Penton manual recommends replaceing the frame if the steering head pockets become oversized! I wish someone would come up with a tapered roller bearing conversion kit, but I see no way without machineing the frame pockets deeper and there's not much material there to go deeper. I believe I saw a post in the archives somewhere. I was almost desperate enough to consider having someone TIG weld the races in, but this 3M seems plenty strong. Good luck and hope this helps. Wildman

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[t20sl]

3M DP-190 strength is only 2750-3500 psi not 190,000 psi. I would use the gray version as it has a much higher strength than the clear version of DP-190.   Another item that has been used for races is Loctite.  Most Loctite like 262, 271 retaining compounds are 3000 psi however they harden in absence of air.  With the race being so narrow I have seen them not cure after several days.  Probably due to air still getting to the compound.  Loctite has gap gilling ability of up to .010" on the 262 version but I still would go with a good grade epoxy.

[wildman]

I'm sorry, my face is red. Even though my races are still holding, I made a mistake in recomending the DP-190. I went with the local vendors recomendation and now that I've looked up the actual product specs I see it's not really the best product to use for this application. I would still prep and clamp as I've suggested but another product like Devcon or even another 3M product would be better. I had almost 0.010" to fill and red loctite would never work, perhaps some other type. Sorry for the bad call, I truly thought it was good stuff (and it is, just not for this application)
Wildman

1975 250 Cross Country, 1974 175 Jackpiner, 1975 125

[DKWRACER]

Wildman et al...Thanks for the communications! Have just rcd the new Super Epoxy, and will be using your technique with "thru bolts" to set in place. And now for the honor.....sure wish our Senators and Congress-persons would take heed of the way we operate:
1=desire
2=a dream
3=communications

Am I not alone?
Our Country needs So much []
Thanks for Sharing, a concept not un-familier to this site

Respectfully, Tom Brosius