Basement Floor Bulkhead Repair Aluminum

Topic: Basement Floor Bulkhead Repair Aluminum (Read 3753 times) previous topic - next topic

Basement Floor Bulkhead Repair Aluminum

December 05, 2021, 11:35:12 am

Rather than covering the how's and why's of the damage (that cat has been sufficiently flattened) I'll just share where I am in my current floor replacement project.
Most who do this elect to use heavier gauge steel tube and coating it. That's a good way to go; the factory installed .062" wall /16ga. uncoated tube is the reason why the floor structure is not going the life of the coach, the only two pieces of .125"wall/1/8" tube are the forward and aft most transverse pieces that bolt to the angle/bulkhead structure. Had they built all of it from that heavier wall tube most coaches would have likely got 40yrs+ of service before it rusted through. You can see in my pics that as bad as mine is rotted out the aft most (1/8" wall tube) is still in tack. I had no separation and no failed rolock fasteners. The only reason I found the problem at all is because I wanted to reconfigure my sewer dump.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #1 – December 05, 2021, 11:52:34 am

Quote from: len.barron – December 05, 2021, 11:35:12 am

The only reason I found the problem at all is because I wanted to reconfigure my sewer dump.

As bad as the rotted steel looks, and yours does look bad, it is still interesting that the damage was apparently not discernible under casual inspection. Your coach obviously did not break in half going down the road, and I assume the floors of the bays were not sagging under the weight of the contents. It is easy to understand how many owners (myself included) could have considerable hidden structural damage, and yet remain blissfully unaware of it.

Please keep us updated on your progress. We are all interested in these extensive reconstruction projects, even if we never actually get personally involved in them.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #2 – December 05, 2021, 11:56:17 am

After finding the damage near the sewer dump and then seeing that I had "rust jacking" of the fiberglass belly skin under much of the tubes I peeled off the entire belly skin. Thankfully the heavy rust stopped about 10" behind the bulkhead just aft of the fuel/propane tank bay. Rather than creating another joint there, I just took the cutout to that bulkhead and created another bolted flange (now the forward section could be removed separately if ever needed). Gutting of the tank bays, water heater, batteries, inverter and aux compressor had to be done before the floor section was dropped.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #3 – December 05, 2021, 11:57:22 am

You mention aluminum in the title. I would NOT mix the existing steel with aluminum.

Thicker steel, coated or painted steel-- just fine.

And, I am surprised that you could not get an idea of the damage by just looking at the FG underbelly. I would have expected the rust jacking to have significantly "pushed down"/"raised" the FG so that where the beams are is much more pronounced than toward the center of the coach where there is not water intrusion/rust jacking.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #4 – December 05, 2021, 11:57:29 am

My background is working in marine aluminum structures/mechanical systems so rather than defaulting to heavier steel, I elected to replace my floor structure with thicker wall aluminum tube, it is far better suited to high moisture environments and even with increasing wall thickness/strength considerably, I will end up with a slight weight savings compared to the poorly executed original floor structure. Having said that; aluminum tube (3/16" wall) is more than double the price of 1/8" wall steel tube and requires considerably more patience for welding/fabrication.
One other plus of aluminum is that it allows me to work on my own safely as I can still pick up and move this entire 8ft x 10ft section on my own (though not as easily as when I was younger).
Post weld fit up test is where I am today.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #5 – December 05, 2021, 11:58:03 am

Quote from: wolfe10 – December 05, 2021, 11:57:22 am

You mention aluminum in the title. I would NOT mix the existing steel with aluminum.

Thicker steel, coated or painted steel-- just fine.

And, I am surprised that you could not get an idea of the damage by just looking at the FG underbelly. I would have expected the rust jacking to have significantly "pushed down"/"raised" the FG so that where the beams are is much more pronounced than toward the center of the coach where there is not water intrusion/rust jacking.

Covered above...I'm entirely comfortable with my material selection.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #6 – December 05, 2021, 12:01:48 pm

That's why we don't drive in the rain if it can be helped. Yes, .125 wall is not going to add very much to the cost of the steel. How much trouble is it going to be to coat the steel? Not much. Nice to have removable panels under the coach so they could be easily pulled to inspect, modify, etc. As it is now, you really have to pull the bottom off to see how bad yours is. Bulging, etc only offers a guess at best.

That's why we will never visit the factory. Too great a chance of going Postal if several topics came up.

Good photos. Bet some will not want to view before dinner!

Pierce

Re: Basement Floor Bulkhead Repair Aluminum

Reply #7 – December 05, 2021, 12:05:00 pm

The key to attaching aluminum to steel is to create an effective barrier, I've already treated all the remaining steel with 2 coats of POR-15. I'll further coat the mating surface of the aluminum with zinc/chromate paint and then wet assemble the joint with a polysulfide sealent (avaition guys know it as "Pro-Seal").

Re: Basement Floor Bulkhead Repair Aluminum

Reply #8 – December 05, 2021, 12:10:50 pm

One other thing I want to point out is the importance of cleaning up and sealing the upper backside attachment of the angle to bulkhead sheet, this is poorly attached with only 5/8" stitch welds and offers considerable gaps where the water splash off the tires will drain right down into the bulkhead/floor mating seam. I cleaned mine up and used a good urethane sealer...I'm probably going to add some more to the verticals as well..

Re: Basement Floor Bulkhead Repair Aluminum

Reply #9 – December 05, 2021, 12:16:06 pm

Quote from: Pierce & Gaylie Stewart – December 05, 2021, 12:01:48 pm

That's why we don't drive in the rain if it can be helped. Yes, .125 wall is not going to add very much to the cost of the steel. How much trouble is it going to be to coat the steel? Not much. Nice to have removable panels under the coach so they could be easily pulled to inspect, modify, etc. As it is now, you really have to pull the bottom off to see how bad yours is. Bulging, etc only offers a guess at best.

That's why we will never visit the factory. Too great a chance of going Postal if several topics came up.

Good photos. Bet some will not want to view before dinner!

Pierce

My greatest disappointment was in the welding of the floor tubes, (beyond the crappy uncoated .062" tube) they only welded the vertical joints so that they wouldn't have to grind the horizontals flat for the skin application...just plain negligent. Even with no rust compromising it there would have been considerable flex...honestly I think they lasted as long as they did because the fiberglass and foam insulation held it all together.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #10 – December 05, 2021, 12:16:36 pm

Len. What type of covering will be going above and below the new frame and what kind of adhesive might you be using to attach it ??

Re: Basement Floor Bulkhead Repair Aluminum

Reply #11 – December 05, 2021, 12:21:15 pm

Quote from: Bob & Sue – December 05, 2021, 12:16:36 pm

Len. What type of covering will be going above and below the new frame and what kind of adhesive might you be using to attach it ??

still kicking that around...I'll probably use a urethane sealant but I'm considering plastics/FRP/aluminum sheets, leaning toward FRP panels now as they really are the best bang for the buck. I've done a lot of aircraft sheet metal work so I'll likely seal/rivet attach the panels in the open areas an then just use some type of threaded fastener for the areas were you can access the through bolts...

Re: Basement Floor Bulkhead Repair Aluminum

Reply #12 – December 05, 2021, 12:24:19 pm

Now on to something I need help with. When I removed my wet tank it was/is full of loose rust (the other two are good to go) I replaced the drier right after I got the coach last year so the source of the problem is in hand...this is just left over damage. Is this configuration of tank still available?

Re: Basement Floor Bulkhead Repair Aluminum

Reply #13 – December 05, 2021, 12:28:09 pm

Quote from: len.barron – December 05, 2021, 12:24:19 pm

Is this configuration of tank still available?

I think Mike (Pamela & Mike) will answer that when he sees this thread. I know he has sources where he can order replacement tanks.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #14 – December 05, 2021, 12:36:55 pm

Quote from: Chuck & Jeannie – December 05, 2021, 11:52:34 am

it is still interesting that the damage was apparently not discernible under casual inspection.

Well, I've only had my coach for 14 months and I found the issue about 6 months ago (just started working it in the past month on the weekends) and was just using it locally both before and after, I had no separation or sagging and monitored it closely after I found the problem.
I'm going to convert the front bulkhead connection to thru-bolting as well while I've got it apart.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #15 – December 05, 2021, 02:19:01 pm

First off that is a sweet job on the replacement floor. To the naysayers (owners of SOB that have caught us at a campground wanting to see the coach split in half due to misinformation) this shows how the floor is just a bolt on part and is fixable.

We have a Truck Parts World here locally that I have went out to and got a replacement tank or 3 from. Truck Parts World | Quality Parts Since 1987 They don't have the exact same tank but they have ones that will work. The bosses may be in different locations and you may have to drill a new mounting hole or 2 but they have always found one that would work. You just need to look around your area and find a good truck supply company and they can help. With us in the middle of the oil field we have several truck supply parts stores around to shop for parts at. NOW don't go in and tell them that you need a wet tank for a XXXX year model Foretravel as you will get the deer in the head light syndrome look. Just take the tank in and put it up on the counter and tell them you need one of these or one as close as possible.

Mike

Re: Basement Floor Bulkhead Repair Aluminum

Reply #16 – December 05, 2021, 02:48:45 pm

Quote from: Pamela & Mike – December 05, 2021, 02:19:01 pm

First off that is a sweet job on the replacement floor. To the naysayers (owners of SOB that have caught us at a campground wanting to see the coach split in half due to misinformation) this shows how the floor is just a bolt on part and is fixable.

We have a Truck Parts World here locally that I have went out to and got a replacement tank or 3 from. Truck Parts World | Quality Parts Since 1987 They don't have the exact same tank but they have ones that will work. The bosses may be in different locations and you may have to drill a new mounting hole or 2 but they have always found one that would work. You just need to look around your area and find a good truck supply company and they can help. With us in the middle of the oil field we have several truck supply parts stores around to shop for parts at. NOW don't go in and tell them that you need a wet tank for a XXXX year model Foretravel as you will get the deer in the head light syndrome look. Just take the tank in and put it up on the counter and tell them you need one of these or one as close as possible.

Mike

Thanks for the lead, I'll definitely look into that; I'm also going to run my boroscope down in it and see just how bad it is...if not too bad I may try the old ball bearing/bb shake&swirl method to clean it out then poor a gallon of evapo-rust in it for a few days to kill the existing rust...of course if I can get a new tank for reasonable money, this one will be in the scrap bin..

Follow-ups
- Slide outs

Re: Basement Floor Bulkhead Repair Aluminum

Reply #17 – December 05, 2021, 05:36:53 pm

I think I know the source of your severe corrosion issue.
According to the where is len.barron, you are located several miles west of San Diego.
Salt water will get you everytime. .
Tim

Re: Basement Floor Bulkhead Repair Aluminum

Reply #18 – December 05, 2021, 07:53:29 pm

Quote from: len.barron – December 05, 2021, 02:48:45 pm

Thanks for the lead, I'll definitely look into that; I'm also going to run my boroscope down in it and see just how bad it is...if not too bad I may try the old ball bearing/bb shake&swirl method to clean it out then poor a gallon of evapo-rust in it for a few days to kill the existing rust...of course if I can get a new tank for reasonable money, this one will be in the scrap bin..

A mixture of 1/4" and 5/16" nuts work better than round objects. Works great on M/C gas tanks that have rusted inside.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #19 – December 05, 2021, 08:32:31 pm

How about welding tabs on the new structure so you could fasten the new covering on without drilling into the tubing?

Good article on steel treatment. Rust Protection

Consider Tube Seal or boiled linseed oil for the interior of steel tubing. This is used in aircraft since the Wright Bros.

Pierce

Re: Basement Floor Bulkhead Repair Aluminum

Reply #20 – December 05, 2021, 08:35:18 pm

Impressive fabricating Len.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #21 – December 05, 2021, 09:37:06 pm

Quote from: Chuck & Jeannie – December 05, 2021, 11:52:34 am

Your coach obviously did not break in half going down the road, . . .

The trusses running the length carry the weight, the boxes underneath prevent twisting.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #22 – December 05, 2021, 10:25:33 pm

Len,have tried both Rust Bullet and POR-15,Rust Bullet much better in my opionion.

Re: Basement Floor Bulkhead Repair Aluminum

Reply #23 – December 05, 2021, 10:36:32 pm

Len good looking project. I'm sure you have addressed this but be aware to properly ground in multiple locations to prevent electrolysis from getting a start, separate from your attachments? Did you use 6061? Are you going to Alodine?
Scott

Re: Basement Floor Bulkhead Repair Aluminum

Reply #24 – December 05, 2021, 11:23:54 pm

Nice looking work.

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