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Topic: My bulkhead experience (Read 7778 times) previous topic - next topic

Re: My bulkhead experience

Reply #40 –
Quote from: wolfe10 –
Morris,

If no distortion and no rust, the worse case is that you will have a few broken bolts to replace.  No big deal.

When that is done, I would recommend using a wire brush on a drill to clean the area from just onto the white fiberglass "belly" around to and including the vertical part of the angle beam where you see the bolts (i.e. to the top of the vertical beam where you see the bolt heads).

Then mask off the top half of the heads of the bolts (so you could still get a socket/wrench on the bolt) and mask off the FG floor (leave 1/2" or so of floor exposed). Spray with automotive undercoating.  One can will easily do both front and back beam areas.

I suspect a reasonable amount of the damage is being done by water migrating in along the threads of the bolts (the angle beam is drilled larger than the bolt threads so that the bolt will torque to the box beam inboard of the angle beam) every time a coach is driven in rain. 

Brett

We brought our MH to our house today.  I wanted to check the bulkhead bolts as one of my very first things.  I used approx. 21 foot-pounds as the criteria (I believe 250 inch-pounds converts to 20.833 foot-pounds.) I checked all the bolts on the front bulkhead, they were all tight with the 20-25 foot-pounds reading on my torque wrench.  I then checked all the bolts on the rear bulkhead.  All bolts except for 2 or 3 were tight with the 20-25 foot-pounds reading on my torque wrench.  The 2 or 3 would rotate at approx. 15 foot-pounds but they did not seem to get any tighter than the approx. 15 foot-pounds reading. they just continued to rotate.  They did not fall out and I did not see any sign of rust on them.

In fact, I did not see any sign of rust nor distortion of the angle frame anywhere on either of the 2 bulkheads.

What do you think I should do concerning the 2 or 3 bolts that rotated at approx. 15 foot-pounds?

Do you think I should use a brush of some type to clean around the bolts to prepare for applying the automotive undercoating?

Thank you.

Re: My bulkhead experience

Reply #41 –
According to James at Xtreme, leave them alone!

Re: My bulkhead experience

Reply #42 –
My guess would be they're stripped out, you might be able to work them out and install the new bolts with nuts.  Bot of they're not side by side, I wouldn't worry about it.  Others opinions may differ.

Re: My bulkhead experience

Reply #43 –
The conservative answer, particularly if the ones that will not torque up are near each other is to remove, drill to 3/8" and thru bolt them.

Brett Wolfe

Re: My bulkhead experience

Reply #44 –
Earlier in this thread were comments on the Rolok bolts being way too to hard to drill the center out.
The Rolok bolts can be drilled out with a good HSS drill bit.
I have 5 bolt heads from the rear bulkhead which came out with about 5 threads and a rusty break where bolt entered 1.5 inch square tube. I put one in the vise and drilled out the center with an 11/64 bit - took less then one minute, however, when the drill bit reached the bolt head it started making noises. These bolts are hard on the outside layer but much less hard on the inside by design (I am a retired Mechanical Engineer).

I have not yet attempted to to remove a broken stud by drilling and using an easy out. Doing this would mean I could replace broken bolts without making 1 3/8 holes in fiberglass belly cover.

Re: My bulkhead experience

Reply #45 –
Here is what I found out when repairing my bulkheads on my 96 36' U270.  First the joints had no separation and only a little rust on the metal angle which I wire brushed off.  I found 4 bolts on the rear bulkhead that were broken at the usual 3 or 4 threads from the head.  Three were at the passenger side end and one about 6 bolts in from the right side on the rear.  The front bulkhead had 2 bolts broken at the end of the angle on the passenger side.  I decided not to remove any of the bolts that passed the torque test, but a couple of bolts did back out with the torque test, so I removed them and replaced with 3/8" grade 8 bolts.  Most of the others  I drilled a new hole alongside the broken bolt.  I also installed new bolts in between every 2nd and 3rd bolt that was not broken. I made 1 1/4 x 1 1/4 x 1/8 backing plates for the locking nuts. There was one place where I used the double nut procedure to remove a broken bolt.  That was difficult as it was well rusted and required an overnight application of rust buster.  I really needed to get that one out as it was near the end of the angle and the only spot for a replacement.  In another post I mentioned that I had some 1 1/2 x 3" tubing in the frame of the basement floor behind front angle.  That was not the case as I found out when drilling for new bolts.  It really was 2 pieces of 1 1/2 tubing back to back.  It did not extend all the way to the ends  but almost.  I had to use 4" long bolts where it was doubled.  I also found a short section at the rear with doubled 1 1/2 on the drivers side at the utility compartment.  Most of the bottom panel at the rear just had one piece of 1 1/2, so 3" bolts for that.  I'm not sure why there is 2 pieces at the front unless it is extra support for the large propane tank.  At the ends of the angle the original bolt went into the hollow part of the metal tube that runs fore and aft down the sides.  All I could do was install a new bolt inboard a little beside that tube.  I also predrilled a  piece of hardwood (maple) on a drill press to use as a guide in drilling the new holes.  I had to shape it a little as metal angle is not exactly 90 degrees on the inside.  I clamped it vertically to the angle where I wanted a new hole.  Had to wing it in a couple of places where something was in the way and I couldn't use the guide.

Before I started any of this, I cleaned and lightly sanded the fiberglass skin near the bulkheads with the intention of re-fiberglassing the holes that have to be made for the nuts.  I drilled a couple of holes with a hole saw and didn't like it for fear of penetrating a tank.  I switched to a Rotozip tool and made small rectangular holes in the fiberglass skin.  That worked well as the bit isn't long enough to go through the upper skin.  I used a small long 1/4" diameter magnet to locate the metal behind the fiberglass.  I could go right up to the metal with the rotozip if needed and around any of the protruding old bolts.  I found a couple of places at the rear bulkhead where there was a piece of 3/4" thick plywood in addition to the foam.  One was at the right side where the water pump and pressure tank are located.  I think it is there for bolting down the water pump.  It had been wet but was not rotten.  The rotozip made it easy to remove enough plywood for the nut and bolt.  I had to go slow though so as not to break the bit.  The other piece of plywood was under the utility storage area next to the fresh water tank with nothing bolted to it and it was like new.  After the bolts were in I foamed the cavity around the nuts.  I haven't done the fiberglassing yet, waiting for good weather and time permitting.

Most of the broken bolts are at the curb side, Maybe water runs to that side because the curb side is usually lower.  Also the fresh water tank overflow is on that side at the rear.  I plan to undercoat the angle and spray the joint next to the angle with Corrosion X HD once a year.  Also maybe relocate/or extend the fresh water tank overflow. 

Think about this, the basement compartments seem to be built like a deep one shelf bookcase with a plank at the top and bottom and 4 vertical planks in the middle with no lateral bracing.  A bookcase would normally have a back made of plywood or solid wood for lateral bracing.  In this case it seems like the only lateral support is from the metal at the ends which is part of the wheel suspension.  I suppose the tanks could provide a little lateral support.  There is a lot of weight down there if the tanks are full, along with the batteries, tools and all the other stuff we carry.  When we step on the brakes it all wants to move forward or a little bit aft during acceleration.  Maybe that is helping to break the bolts.  I also notice that there is a row of these same bolts across the bottom at each of the inner bulkheads.  I didn't do the torque test on them or notice any missing.  My bolt man said that my bolts are not Rolok as Rolok has a trilob slightly spiral shape to the threads.  The 2 unbroken ones I removed are round and threaded to the point on the end and are hardened.  They will form threads when screwed into a softer metal such as mild steel. 

I checked all the welds I could see for cracks and didn't find any, did find a leaking shock.  Thanks to Brett Wolfe and all the others who provided advice about this problem. 

Re: My bulkhead experience

Reply #46 –
A couple weeks ago, I torque tested the bolts on my bulkheads.
Like yours, my bulkheads show no separation and little rust on the metal angle. 
Like yours, three failed bolts on the rear bulkhead were at the passenger side end. and I wonder if that is just a coincidence.
I wonder how many others have three bolts on the rear at the passenger side end that have failed?

My front bulkhead had no bolts that failed the torque test while the rear bulkhead had 7 bolts that failed, including one that already had another bolt installed a quarter inch away.
I had one loose bolt at the driver side end on the rear. It torqued OK when I removed and reinstalled it. I noticed that it did not appear to be a ROLOK bolt.

Re: My bulkhead experience

Reply #47 –
A lot of discussion on bulkhead repairs..FOT and MOT check only visual. IF no separation and very little rust they will not torque.

FWIW.

Re: My bulkhead experience

Reply #48 –
Well, here is my experience at MOT for my Bulkhead inspection/repair -
 
From today's invoice as I picked up the coach
 
"Seal/Clean/Check Bulkhead and Bolts -
 
"Drilled and installed two new bolts to replace two missing bolts, cleaned bulkhead. Aluminum strip underneath was falling down,  - reattached. Painted and sealed bottom edge of bulkhead and aluminum strip"
 
Total labor Charges - $84.00
 
Total parts - Bolts and Paint - $6.71
 
I don't think I will be selling the coach any time soon for fear of bulkhead issues or cost...:-)
 
Mike Rodgers did say if they see significant issues - they do not attempt repair and refer the client to FOT since they do not want to get into major bulkhead repairs due to liability concerns.

Re: My bulkhead experience

Reply #49 –
Tim,

Seems like a very reasonable charge.

To All:

I can understand why the factory bolted the sections together but would not it make more sense to weld the sections for repair rather than re-bolt them? I assume that this is all mild steel. 

Re: My bulkhead experience

Reply #50 –
I think the proximity of the steel to the fiberglass, foam insulation and wood would prevent welding.

Re: My bulkhead experience

Reply #51 –
John,

Accessing the area to weld would be very difficult and the sandwich material in the basement floor (where you are working) would not tolerate heat.

Through bolting is a good fix.

Brett Wolfe

Re: My bulkhead experience

Reply #52 –
Guys, just started this bulkhead inspection and have three 4 or five thread bolts, and 2 more that torque  CW to 20 but CCW they back out, so I suspect they are broken....How long were the original rolocks?  Do you have to use the hole say to get the remainder of the bolt out ...How much room do you have up front before you hit the fuel tank.....I have searched the forums, but still do not have a clear idea of what has to be done....thanks,      Dave and Wendy 99u320,  05 mini cooper

Re: My bulkhead experience

Reply #53 –
Dave,

You will never hit the fuel tank.  The Roloks thread into the beams below the floor of the fuel tank compartment--  floor of coach below the beam and floor of the basement above.

The standard Rolock used in the Foretravel bulkhead assembly is 3" long.  Some of the newer coaches have longer bolts threaded into two 1 1/2" box beams at the outboard ends of the bulkheads, so those bolts will be longer.

And you will need to drill a hole in the floor to access the "back" of the Rolok and to install the washer and nut on the new bolt to replace the Rolock.

See my earlier post for plug part numbers, etc.

Brett Wolfe

new rolocs?

Reply #54 –
has anyone ruled out putting new rolocs, into new drilled holes?

Re: My bulkhead experience

Reply #55 –
Since I have no bulkhead separation, that is exactly what I intend to do. The old ones have funtioned for 17 years, I would be happy with another 17.

I purchased a dozen new Roloks from the parts department when I was at FOT last month. I will drill new holes next to the old ones when I get a chance and install the new bolts.

Thanks for all the input

Reply #56 –
Just finished the bulkhead repair on the back of our 99u320, and am sure the front will go rapidly...Could not have done it without all the info available here..

For what it is worth,  Foretravel now has a kit, with the caps, bolts, and rolocs, for those who do not want to track them down on their own......

Re: Thanks for all the input

Reply #57 –
Hi,
 
Hum...how much for the kit?
 
Jim
2002 U320
 
Quote
Just finished the bulkhead repair on the back of our 99u320, and am sure the front will go rapidly...Could not have done it without all the info available here..
 
For what it is worth,  Foretravel now has a kit, with the caps, bolts, and rolocs, for those who do not want to track them done on their own......

Re: My bulkhead experience

Reply #58 –
Quote
Hum...how much for the kit?
From Don Hay 1992 U280 36' 11/12/09
I learned that FOT Parts sells a "kit" to fix the bulkhead separation, so this afternoon, I went over to Parts and found out the contents of the kit:

  1. There are 8, 3/8", 2 ½" long, grade 8 bolts with flat and lock washers and nuts.
  2. Also, at least an equal number (I think there were more like 10) of "roll-lock" bolts. These look like lag bolts and are what was installed originally. They are 3" long, 5/16" diameter, black steel. The inside head of the bolt has grooves in it that dig in to the angle iron, preventing the head from vibrating/backing out.
  3. 8 plastic plugs for the nuts on the through-hole bolts.
  4. No instructions included, so parts put me through to Mark Harvey, who patiently explained to me:
      a) For the 3/8" bolts, holes must be drilled large enough for the bolts to pass cleanly through both angle iron and square tubing.
      b) Square tubing is not the heavy-duty tubing used for the side frame , but a thinner tubing used for internal support.
      c) It would be possible to crush this tubing if too much pressure were placed on the nuts. Therefore the recommended torque on these heads is 20 ft-lbs, or for a "mechanically inclined" person, 'firm but not excessive' was the description.
      d) When drilling the holes for the "roll-lock" bolts through the angle iron, the holes have to be larger diameter than the 5/16" bolt, so it passes freely through the angle iron.
      e) In between the angle iron and the square tubing is a piece of "sheet steel" (I couldn't detect any in my coach); must also drill the larger hole through it.
      f) The hole in the square tubing should be 9/32" or smaller, for the roll-lock bolts to grip into. He said smaller would work to grip better, but would be harder to torque into tubing. No mention of torque limitations for the roll-lock bolts.
  5. Mark said that the 3/8" bolts and nuts are designed to pull the angle iron and square tubing together.
  6. Then, the roll-lock bolts are installed between through-hole bolts to firmly connect the components together. The kit sells for $35. If Wayne is using huck bolts, then I doubt that he is even using this kit. That would indicate that it is intended for us do-it-yourselfers That's about it.

http://www.beamalarm.com/Documents/bulkhead_separation.htm

Re: My bulkhead experience

Reply #59 –
Barry or anyone who has seen one of these kits,

Are they still using the 1 3/4" NON-waterproof plugs or have they switched to the 1 3/8" waterproof plug (same manufacturer) as I used.

I recently did a mechanical inspection on a coach with the original style 1 3/4" plugs, and all but one had allowed water to leak into the joint area.

1 3/8" is the largest water proof plug they make and it IS large enough to work through.

Brett Wolfe