Materials for bag seals and other uses

[Peterbug]

As I read about TM owners replacing bag seals, Hypalon (discontinued in 2009 and now sold as off brand csm material) comes up and I did some internet research on alternatives. Today the Google algorithm suggested the following article on alternative material generically known as TPU. I hereby share the link and invite anyone with experience or information to share their wisdom. https://erez-therm.com/rib-collars-made-from-polyurethane-fabric/
It may be useful in other applications.

 

[Bill]

This sounds like a great find. Thanks for finding it and posting it.

Unfortunately, the web site isn't very informative, so you would have to accept their "invitation" (demand?) for a personal consultation. By doing so, you could find out about such things as
o Minimum order quantity
o Stiffness - forming a bag seal requires rather tight bends
o Flexibility - once formed, a bag seal has to be readily compressible (squishable)
o Details of the heat-welding technique, and the possibility of other bonding methods
o Surface roughness - the bag seals rub on the paint as the trailer is opened and closed
o And of course, cost in small quantities

Peterbug, if you have any info on any of these parameters, we would love to hear it. Or if anyone here is near their US office in Hillside, NJ (a bit south of Newark), perhaps a quick visit would be fruitful.

I wonder what the factory is currently using for bag seals? Most likely the off-brand CSM material. While it is not a perfect solution, the advantage to us owners is that the factory buys reasonably large quantities, and is willing to sell us small quantities.

Bill

 

[Larryjb-HILO]

Very interesting Peter. If anyone manages to try this stuff out I'll be curious to see how it fares. I remember people using marine grade vinyl. I haven't heard any followup on this material, so I assume it has held up to the test of time.

While on the discussion of materials for the bag seals, the topic of foam always seems to get left out, so I'd like to ask it here as well:

What have people used:
memory foam?
low density? medium density?

What dimensions did they use?

 

[kjbooe]

Interesting info. Is this to replace the seal material that connects the 2 halves together when putting the tm up?

 

[Larryjb-HILO]

I think Peter is suggesting this new material might be used in this application (any seals exposed to sunlight). However, Bill raises some good points too. The original vinyl covered seals were quite slippery by nature so as to not scrape or scratch the paint on the walls of the trailer. Is this new material slippery enough to satisfy that condition?

The intended purpose of that new material is great for strength and UV resistance. It may or may not have the appropriate flexibility or slipperiness that would be ideal for our purpose. Perhaps some one (maybe Peter?) would be able to contact the company to get a sample for testing.

 

[Bill]

Interesting info. Is this to replace the seal material that connects the 2 halves together when putting the tm up?

I'm not sure if you are referring to the flat white panels inside the front shell that velcro into place when the front shell is up? Or the so-called "bag seals" - long skinny bags stuffed with foam that fill whatever gaps exist between the two shells, or between the shells and the body. For example, there is a bag seal between the roof of the rear shell and the ceiling of the front shell, when both shells are up.

I believe Peterbug is referring to the bag seals.

Bill

 

[oldstick-TMO]

Very interesting Peter. If anyone manages to try this stuff out I'll be curious to see how it fares. I remember people using marine grade vinyl. I haven't heard any followup on this material, so I assume it has held up to the test of time.

While on the discussion of materials for the bag seals, the topic of foam always seems to get left out, so I'd like to ask it here as well:

What have people used:
memory foam?
low density? medium density?

What dimensions did they use?

The original in ours was plain-jane low density foam rubber. I found a bag of foam rubber sheets when Hancock fabrics was going out of business. Approximately 18 x18 sheets, and about an inch thick. I just cut strips and rolled those inside the marine fabric.

 

[Larryjb-HILO]

Thanks Oldstick,

So the foam is "rolled" inside instead of square or rectangular blocks? I guess I'd have to see how they are inserted when I remove my seals.

 

[Bill]

I would think (but I don't know) that you might want to buy closed-cell foam. Open-cell foam might soak up water, and encourage mold / mildew on the bag seals.

Bill

 

[oldstick-TMO]

Thanks Oldstick,

So the foam is "rolled" inside instead of square or rectangular blocks? I guess I'd have to see how they are inserted when I remove my seals.

I should have just said "inserted". If I recall the original was just rectangular strips of open celled foam 2 or 3 inches wide. Like Bill said, I think using a denser foam when replacing might be better, but it still needs to be pretty springy to help with the seal.

Pic of one scrap piece here.

https://www.trailmanorowners.com/forum/showthread.php?t=15153&page=4

 

[Larryjb-HILO]

Thanks Oldstick, Bill, this has been very helpful. I had wondered if TM used a cheap foam (it sounds like they did). I like Bill's idea of a closed cell foam, but it's good to know that it needs to remain quite spongy. That rules out memory foam.