Can you weld the nuts onto the plates and then vhb the plates, thus eliminating the need drop the tanks to get a wrench on them?

 

Here is my L track solution. The guy who makes the metal bases stopped doing it a few years ago. Seats are from a Toyota van. The name of the company that makes the interface product between the base and the L track is Unwin. I think it’s British. The seats can move anywhere on the track or be removed.
I had to lower the tank somewhat to bolt the L track in. It was a total pain to find the areas I could drill. I must have gone under that van 100 times. I don’t think I would want to do it all again especially because I broke my leg 7 months ago and all that up and down and crawling on the ground or on a creeper would be much more difficult currently. Still recovering.
I’m going under there again to hook up a Velit heater soon but that will be a whole lot easier than the L track.
I can get better pics if you if you need them.

 

Mount ford transit seat base rails directly to the floor, through the chassis to backing plates and nuts in the other side.

get a woodworking shop to CNC router your floor plywood to the correct shape to slot down around the rails. Use the cut plywood as a template to cut out your floor xps insulation to the same pattern/cutout

You’ll have to measure to see the right thickness for floor xps and plywood to that the rails are just sub flush but you can still mount a transit seat to them.

3d print covers to go over the seat rails when the seats are not installed.

more or less mimics how the passenger van floor is designed

For me I just used flanged l track through bolted (with an aluminum spacer under it). I want it to help hold my floor down. I’m never going to remove my floor.

 

I'll second the idea of welding nuts to metal plates. Then adhere the plates to the underside of the van. VHB, epoxy, construction adhesive, windshield urethane, etc.

 

I used cage nuts on a steel bar. The bar was held in place by two small countersunk screws. If you have a 3D printer, you could make your cage and use appropriate nuts.

Floating Nuts:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

If you have welding skills, check out the "weld nuts" $25 for 25 of them (1/2"x20). Fine threads let you use aircraft-spec'd bolts.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

AN8 Bolts ( 1/2-20 ) | Aircraft Spruce ®

AN8 Bolts ( 1/2-20 ) Hex head aircraft bolts are made of high-strength type 4037 or 8740 alloy steel (type 8740 is most commonly used).

www.aircraftspruce.com

You want at least 4" of surface flange area per bolt (to prevent pull-through in a crash). No sharp edges, smooth radius end (spread the load). Ford uses a flange reinforcement on passenger vehicles (crawl under to take a look at one).



Seat belts are 7/16-20 TPI. USA safety standard, which is why I opt for at least 7/16" hardware. Still, I also consider using up to 1/2" hardware and aircraft-grade components for such a critical application.

 

Hi GregoryX,

We have a few seating solutions for use in Transit cargo vans. We have a couple of different seat sizes and we can combine our seats to form a row of seats like a row in an airplane if needed. We just received a Flip-Up double bench seat which is really comfortable, reclines, and frees up a ton of space when stowed away.


Once our mounting plate is installed it stays in the floor and our seat(s) bolt to it via 5 bolts, making the seat(s) removable in less than 3mins with the help of a powered wrench.

If you would like to chat about options/ideas please fill out the “contact form” on the site and I’ll give you a ring to review your use case and make suggestions.


Thanks,


Henry

JMG SYSTEMS



Swivel Captain Chairs

Cargo Van Dual Captain Chair Solution FMVSS Tested

JMG Systems LLC offers on Cargo Van Dual Custom Captain Chair, Conversion Van Seats Tested to DOT/FMVSS 207/210 Safety Standards.

www.jmgsystemsllc.com

Flip-Up Double Bench seat

Flip-Up Bench Seat

<meta name="description" content="The Flip-Up Bench by JMG Systems is a sleek, space-saving seating solution for vans. Built for comfort, safety, and flexibility in any van layout.">

www.jmgsystemsllc.com

 

Can you weld the nuts onto the plates and then vhb the plates, thus eliminating the need drop the tanks to get a wrench on them?

An interesting thought... 🤔

...
Here is my L track solution. The guy who makes the metal bases stopped doing it a few years ago. Seats are from a Toyota van. The name of the company that makes the interface product between the base and the L track is Unwin. I think it’s British. The seats can move anywhere on the track or be removed.
I had to lower the tank somewhat to bolt the L track in. It was a total pain to find the areas I could drill. I must have gone under that van 100 times. I don’t think I would want to do it all again especially because I broke my leg 7 months ago and all that up and down and crawling on the ground or on a creeper would be much more difficult currently. Still recovering.
I’m going under there again to hook up a Velit heater soon but that will be a whole lot easier than the L track.
I can get better pics if you if you need them.

This is basically what I'm looking at right now: adding a couple pieces of L-Track to bolt the seat to; but that makes the floor a permanent install... that's the question, right now.

I used cage nuts on a steel bar. The bar was held in place by two small countersunk screws. If you have a 3D printer, you could make your cage and use appropriate nuts.

Floating Nuts:

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

If you have welding skills, check out the "weld nuts" $25 for 25 of them (1/2"x20). Fine threads let you use aircraft-spec'd bolts.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

AN8 Bolts ( 1/2-20 ) | Aircraft Spruce ®

AN8 Bolts ( 1/2-20 ) Hex head aircraft bolts are made of high-strength type 4037 or 8740 alloy steel (type 8740 is most commonly used).

www.aircraftspruce.com

You want at least 4" of surface flange area per bolt (to prevent pull-through in a crash). No sharp edges, smooth radius end (spread the load). Ford uses a flange reinforcement on passenger vehicles (crawl under to take a look at one).



Seat belts are 7/16-20 TPI. USA safety standard, which is why I opt for at least 7/16" hardware. Still, I also consider using up to 1/2" hardware and aircraft-grade components for such a critical application.

Very helpful. I hadn't thought of caged nuts, either... and I'm not the welder, so anything that could avoid the welding would be ideal - though I have a friend who can do it for us.

And the large surface area is a good reminder. The seat-base we bought came with large (3-4" x 1/4") steel plates for this purpose; that makes sense with your description.

Some mix of these ideas are starting to gel... 🤔

...
We have a few seating solutions for use in Transit cargo vans. We have a couple of different seat sizes and we can combine our seats to form a row of seats like a row in an airplane if needed. We just received a Flip-Up double bench seat which is really comfortable, reclines, and frees up a ton of space when stowed away.
...

Thanks for the nudge. I guess it wasn't clear in the first post that I've already got the Broad Arrow 860 and a swivel base and that's all looking good. While we considered the flip-up, that doesn't meet the needs of this particular van.

 

I'll second the idea of welding nuts to metal plates. Then adhere the plates to the underside of the van. VHB, epoxy, construction adhesive, windshield urethane, etc.

Method of adherence needs to withstand torque needed to tighetn bolt.
Shear strength of JB Weld is 4k PSI or more looks like that is at least 8X what is saw forVHB tape .
(measurments are "lap" shear, not sure how that translates to the angular shear in this case, somewhat similar?)

I have considered L-Track (already purchased) for this as well... but then I still have the floor through-bolted and can't be removed without removing both tanks.

FWIW on the US cargo website, they make the claim on all of the variants of their track is as strong as any of the fittings that they sell (4-6K lbs ea)... with the disclaimer as to the strength of how the user mounts it ... obviously. So it seems like that is a viable approach.

Mount ford transit seat base rails directly to the floor, through the chassis to backing plates and nuts in the other side.
get a woodworking shop to CNC router your floor plywood to the correct shape to slot down around the rails. Use the cut plywood as a template to cut out your floor xps insulation to the same pattern/cutout

You’ll have to measure to see the right thickness for floor xps and plywood to that the rails are just sub flush but you can still mount a transit seat to them.

Search around the forum, there are some posts from folks that have flush mounted factory braskets into the floor on a cargo and/or replaced the factory floor in a passenger and left some/all the brackets in place. IIRC those were all/most? factory seats so probably not much help on the seat part. Maybe one or two on adapting minivan seats. At one point there was someone commercially making an adaptor but I think no more, but maybe some ideas if you can find it. One more thing, if mounting OEM brackets 90 degrees from factory design, need to be comfortble with any impact on crash performance or modify to address. (Forces are most all moved to one weld of the "bail" and along narrow dimension of u-shaped "track. M

Regardless of the approach you choose it would be prudent to remove all compressible material (plywood, insulation, etc) at the bolting points and add some metal to achieve the desired height.

I'd lean towards the glued plate. Seems like the simplest and leaves the smallest size obtrusions when the seat is removed. Downside is if the adhesive does fail, also need to make sure the fastener does not rust. Probably good to "exericise" the fastener if not removing the seat somewhat regularly ... well if removing the seat somewhat regularly, the the oem seat rails might make more sense, cuz quick release?

Trying to think what advantage the L-track would have if you don't plan on using the adjustability, in which case the track would need to extend into the aisle . Any reason you would want to run with the seat not against the wall say for storing something behind the seat sometimes.

OH wait, are you planning parallel or perpendicular to the wall. I suppose if perpendicular then maybe ajustable for mini vs full sized people, Well unless that is already a feature of the seat. I suppose the cut out and maybe plug for when no seat are simpler than with the Ford bracket? But the mounting is probably the most involved. How many through bolts are needed ... do you have all of them. Dunno what all is involved in the adding the connectors to the seat? Also seems like it would collect the most crap in the track. Well, maybe not, I suppose you could print a plug for the unused area.

tl-dr
Option 1 - if seat is not removed very often/ want simplest install / least residual mounting presence when removed
Option 2 - if seat is often removed and convinience of removal is valued /worth more complex install
But ?? How much value is there to removng the seat when only travelling with 2 folks?? **
Option 3 - if there is value to ability to adjust the placement of the seat


** FWIW - I don't often remove 2nd row seats in minivan, but when I do the quick release sure is nice.

 

I second Argonaut: bolt Ford seat rails to the steel floor. You may find a way to utilize them as bomber attachment points when the seat is removed, via the steel cross bars or the U-shaped rails themselves where a large steel washer/plate can be slotted. For those unfamiliar, the seats are deceptively very heavy. I like the quick-release this affords.

My install:

• rail mounted in steel valley
• 1" XPS atop steel ridges with full length excised rail slot
• 23/32" Advantech routed only where necessary to provide clearance for the rail (underside) and seat bottom (top)
• the top of the steel bar (seat attachment point and highest part of entire rail piece) sits approx 1/2" below Advantech walking surface, leaving space for a stout, flush fit, filler piece when the seat is not in use.

 

If you use L track the length has to go far beyond the back of the seat. It extends the force of a crash to many fasteners and also translates the vector to a horizontal the further back you go. Instead of pulling up at the back of the seat and popping up and out a short piece of L track you’d have to pull the entire thing out using the strength of many fasteners at progressively shallower angles.
It’s a big job. The other suggestions given here make more sense. It’s less effort I would think.

 

I knew I should have posted photos! 😏

This is a Broad Arrow 860 seat on a pre-made swivel / base. The base mounts are along the front-to-rear sides of the base. They are 20" on center from left to right bolt-holes. The width of the base mount-points is ~1" or so. The position shown below has the inner / right-side bolts lined up with a "valley" on the floor of the van and the outer / left-side bolts hit a larger "low" portion of the van's steel floor.

Here's the seat on the base, facing forward.

And rotated:

And in "bed mode" - using the swiveled driver's seat to extend the surface.

Thus far, from the feedback above, I'm leaning more toward the captured nuts setup without L-Track. I'm thinking about it... and maybe it's as simple as buying some captured bolts (with wings) and bolting THEM to the plates, then bolting the plates to the bottom of the van.

I'm also pondering a similar setup but I get nuts welded in the exact spots for the seat-mount - on a 1/4" thick steel bar, IOW - then bolt those to the bottom of the van with small through-bolts so they stay in place while being tightened. That would probably be the most secure - huge plates and I can be certain I'm using appropriate grade nuts. Or would welding the nuts alter the grade? I don't see a grade on the "designed to be welded on" nuts.

Thanks to y'all for the input / ideas!

Pondering... 🤔

 

I am not a fan of L track on floors and kids. Too many sharp edges.

 

Use a product like these seat belt anchor plates on the underside of the van. Hold them in place with some seam sealer or epoxy. The nut will be captive, and you could remove them (with difficulty) if you ever need to.

Pardon Our Interruption...

 

Hm. Nope. Those won't work. They don't "capture" the nuts... they're just mount plates. Meaning one has to get a wrench onto the nuts. Meaning removing the fuel tank. 😁

 

I think I may buy a welding machine... this might be the perfect can't-hurt-to-try opportunity... 🤔

 

I asked AI about welding the nuts to secure the seat and it strongly recommended against it. However with a welder you could certainly weld up a solution where the nut is captive but not welded. Then you could use grade 8 or automotive hardware and not worry about the nut rusting onto the bolt.

I got a MIG welder decades ago. My welds look like crap, but I feel like it gives me a superpower.

 

I was able to sneak bolts and 3/16 stainless steel plates just over and past the rounded edge of the gas tank. They make a wire/spring gizmo specifically for threading them into tight spaces. They often come with the tow hitches purchased from ETrailer. Amazon has them too.

 

How about a plate that's wide enough to span to easily accessible bolt locations? Then mount the base to that. I had a seat mount in one of my vans that had a plate I mounted as a 3rd seat in one van. Threw a latch , and the seat came out. Don't forget seatbelt points too. Maybe adapt a seat from a minivan.

 

Good idea to have a look at how anything significant like seats, belts or tie down points all have some reinforcement underneath.

I used a transit seat in my promaster. (Researching and shopping for the bench seat were my reason for joining the transit forum)

I wanted a raised position to match the front seats. I made a pair of sturdy risers duplicating the rail mount geometry. I made reinforcement angle plates with nuts welded to them, under the van. The angle plates are bolted and sikaflex 221'd to the sides of the unibody cross beams or longitudinal main structure.
No welding on the van, except initial tack weld of the large nuts to the reinforcement plates, once everything lined up. Then took out, welded the nuts more securely, cleaned up and painted, etc. Then reassembled with adhesive. I wouldn't weld to the van for this type of thing, the metal is pretty thin.

https://photos.app.goo.gl/tE3uow7uLCr68eHA7

 

How about a plate that's wide enough to span to easily accessible bolt locations? Then mount the base to that. I had a seat mount in one of my vans that had a plate I mounted as a 3rd seat in one van. Threw a latch , and the seat came out. Don't forget seatbelt points too. Maybe adapt a seat from a minivan.

Wouldn't that be nice? No chance of a single plate. There's beams segregating where just the four main bolts would go... but once it's bolted, it's good. The Broad Arrow seats include the seatbelts.

...
I used a transit seat in my promaster. (Researching and shopping for the bench seat were my reason for joining the transit forum)
...

Thx for the input. Nice work getting it to work there!

 

Note that ISO Class 10.9 and Grade 8 hardware will loose its temper when welded. The result will be the strength of mild steel. When torquing 10.9 or 8 bolts into those de-tempered nuts, they will strip or yield. Don't weld them!

Instead, place a second, thinner steel plate over the structural plate. Cut hex bolt patterns in the second plate that align with the nuts and bolt pattern. Use flange nuts. Then sandwich the nuts between the structural plate and the secondary plate to capture the nuts. Screw or glue the two plates together.

 

FWIW, I ended up NOT welding the weld-nuts. I used captured floating nuts and they're mounted to Rivnuts (nothing to do with the structure / strength - just to hold them in place), keeping the captured nut un-affected by heat or anything else.

One example: 1/2" bar is just to level the mount between rib/valley; bar and disc have holes drilled through them for the mount bolts; those bolts go into rivnuts in the sheet-metal; 12.9 bolts come through from the L-Track on the top into these captured nuts. In my mind, this seems pretty solid - with energy spread through that round plate (that came with the seat-base we purchased). Hopefully, we'll never find out if it's not solid. 🤞

 

Look at Cleco - used in airplane construction - come in several diameters -
very Strong - easy install / remove -