Jump to content

Re-bedding Jib Tracks Today


Recommended Posts

Finally getting around to the track re-bedding job today. I can't find the good advice on an earlier thread about doing this properly. In another thread I noted that in the original installation they had ground off the bolts at the nuts, then glued headliner over it. Some of you wisely advised to size the bolts exactly rather than have to grind them, which I've done. Re-fit under side decks with headliner panels, now mounted to furring, which gives me more room to work with re the bolts. I want to make sure I do the re-bedding job right so that there are no leaks onto my nice headliner panels. 

I have the gray butyl tape, and the hand tool for beveling the bolt holes a bit. Any more secrets? My plan is to

-remove the tracks

-clean up the deck and tracks with acetone

-bevel the holes slightly

-mount the butyl tape on the track and put back in place

-push the bolts through and tighten

Anything I am missing??

image.png.cb478ca8d9208378c434a5924cdc638c.png

Link to post
Share on other sites

Looks like you have the bed-it butyl from Rod at marine how to.  I follow his guidance and wrap the underside of the bolt heads with a thin ring of butyl. Then install all the bolts through the track and add a small cone of butyl around each bolt against the underside of the track.  And then butyl on the underside of the track.  Lower the track and bolts onto the deck all at the same time.  Don't allow the bolts to rotate during tightening. 

Is the deck cored?  If it is now would be the right time to seal the core using the drill, epoxy fill, drill method.  Rod has a good how to for that.  

Link to post
Share on other sites

Thanks- wrapping the undersides of the bolts etc were the parts I couldn’t remember. 
solid glass under my tracks.

10 minutes ago, yoyo said:

Looks like you have the bed-it butyl from Rod at marine how to.  I follow his guidance and wrap the underside of the bolt heads with a thin ring of butyl. Then install all the bolts through the track and add a small cone of butyl around each bolt against the underside of the track.  And then butyl on the underside of the track.  Lower the track and bolts onto the deck all at the same time.  Don't allow the bolts to rotate during tightening. 

Link to post
Share on other sites
43 minutes ago, yoyo said:

Looks like you have the bed-it butyl from Rod at marine how to.  I follow his guidance and wrap the underside of the bolt heads with a thin ring of butyl. Then install all the bolts through the track and add a small cone of butyl around each bolt against the underside of the track.  And then butyl on the underside of the track.  Lower the track and bolts onto the deck all at the same time.  Don't allow the bolts to rotate during tightening. 

Is the deck cored?  If it is now would be the right time to seal the core using the drill, epoxy fill, drill method.  Rod has a good how to for that.  

I like that ^^^ approach...mostly. I wouldn't bother with butyl under the heads. Could be a good place for Tef-Gel or the like. Putting the bolts thru the track before mounting, then wrapping with rings of butyl is how I would proceed. Much more tidy. I don't bother with butyl under the entire track...what is the point of that? No leaks possible there. More is not better.

If those fender washers are the generic thin ones and your backing is anything softer than metal plate or G-10 then they are worthless. They will cup, crush the  backing or laminate, and release pressure on the joint at the wrong time. 3mm (1/8") heavy fender washers minimum. Might be okay with solid glass or plywood cored deck....history would tell.

Link to post
Share on other sites
1 hour ago, Israel Hands said:

Finally getting around to the track re-bedding job today. I can't find the good advice on an earlier thread about doing this properly. In another thread I noted that in the original installation they had ground off the bolts at the nuts, then glued headliner over it. Some of you wisely advised to size the bolts exactly rather than have to grind them, which I've done. Re-fit under side decks with headliner panels, now mounted to furring, which gives me more room to work with re the bolts. I want to make sure I do the re-bedding job right so that there are no leaks onto my nice headliner panels. 

I have the gray butyl tape, and the hand tool for beveling the bolt holes a bit. Any more secrets? My plan is to

-remove the tracks

-clean up the deck and tracks with acetone

-bevel the holes slightly

-mount the butyl tape on the track and put back in place

-push the bolts through and tighten

Anything I am missing??

image.png.cb478ca8d9208378c434a5924cdc638c.png

Where's the beer?B)

Link to post
Share on other sites

Don't forget a spare pair of hands for the other end of the machine screws.

Also, be sure to clock the fastener heads to preclude negative OCD reactions in future.

Other than that you've got it covered.

  • Like 1
Link to post
Share on other sites

Based on my experience with butyl tape, it will squeeze out over time (days) and you may need to re-tighten the bolts.  The squeeze-out may also interfere with the cars sliding, so you might have to dig out the excess.  Don't have any better suggestion though!

Link to post
Share on other sites

A hand chamfering tool? Don't you have a drill available?

You don't want a "light" chamfer, you want enough butyl in the chamfer to easily fill the threads and form a substantial gasket. With M6 screws, I'd want at least a 10mm diameter chamfer. If the underside of the track is wide enough to go to up to 11 or 12mm and still have a few mm of track on either side of the chamfer, that's what I'd do.

  • Like 2
Link to post
Share on other sites
7 minutes ago, IStream said:

A hand chamfering tool? Don't you have a drill available?

You don't want a "light" chamfer, you want enough butyl in the chamfer to easily fill the threads and form a substantial gasket. With M6 screws, I'd want at least a 10mm diameter chamfer. If the underside of the track is wide enough to go to up to 11 or 12mm and still have a few mm of track on either side of the chamfer, that's what I'd do.

I fine that countersinks in a drill tend to chatter and leave octagonal chamfers in glass.

A hand countersink as shown is much preferable - only takes a few twists to leave a nice chamfer.

I've been doing it that way for decades and never had a leak in a hole prepped that way.

Link to post
Share on other sites

Fair enough. I've got some bits that chatter in glass and others that don't so I suspect the quality and condition of the bit has a lot to do with it. In any case, slow and high pressure works best for me.

Link to post
Share on other sites
41 minutes ago, SloopJonB said:

I fine that countersinks in a drill tend to chatter and leave octagonal chamfers in glass.

run it backwards. no chatter, easily controllable, takes only marginally longer, and if the holes aren't perfectly round who cares? hey'll be under the track anyway. the important part is giving enough surface area for the butyl tape.

  • Like 1
Link to post
Share on other sites

Agreed with everything above. 

Putting the bolts through first and then installing the track in one piece is the ideal, however with the number of bolts on even a straight track you'll probably still end up poking them out. 
My track actually has a slight curve to match the edge of the deck to cabin side, but not being pre-bent you have to install the bolts one by one.

 No need to butyl the whole base either, its just more shit to squeeze out, ring around all the bolts & a small countersink is more than sufficient. 

Link to post
Share on other sites
On 4/11/2021 at 12:07 PM, IStream said:

Fair enough. I've got some bits that chatter in glass and others that don't so I suspect the quality and condition of the bit has a lot to do with it. In any case, slow and high pressure works best for me.

 

Link to post
Share on other sites

If you do not tape under the bolt heads & under the entire track, salt will get in there & corrode the track. A little extra work now will result in a much better look a few years later on. ANY place salt water can get into & sit & concentrate will create corrosion - don't give it a chance.

  • Like 2
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...