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Lotus Europa Forums => Garage => Topic started by: buroz on Tuesday,April 16, 2024, 08:34:00 AM

Title: Padding between chassis and body
Post by: buroz on Tuesday,April 16, 2024, 08:34:00 AM
I have restarted my ground up restoration project after pausing it for >10 years.
I'm starting to get close to putting the body back on the chassis and I remember there was some form of padding between the body and chassis (down the central tunnel) to stop vibration. Is there something specific to use/people recommend?
Title: Re: Padding between chassis and body
Post by: 4129R on Tuesday,April 16, 2024, 08:59:19 AM
Be very careful not to put too thick a material on top of the metal chassis or the two bolts holding the seat belts into the centre tunnel will not line up, and you will end up drilling bigger holes through the oval bobbins cast into the shell, which is not ideal.

I used thin underfelt.
Title: Re: Padding between chassis and body
Post by: jbcollier on Tuesday,April 16, 2024, 09:15:03 AM
The stock material absorbed moisture and promoted corrosion.  RD sells a closed-cell foam alternative that is much better suited to the application.
Title: Re: Padding between chassis and body
Post by: Fotog on Tuesday,April 16, 2024, 11:19:39 AM
Since you've had, lets say... a little pause in your restoration,  you might not be so well informed of the parts sources.

RD is R.D. Enterprises in Pennsylvania, USA:  https://www.rdent.com/ (https://www.rdent.com/)

I hope it all goes well.  These cars are a lot of fun to drive, for sure!
Title: Re: Padding between chassis and body
Post by: berni29 on Tuesday,April 16, 2024, 11:38:32 AM
Hi

I looked into this quite extensively for my plus 2 and ended up ordering the standard matting for both my cars. I will be spraying the lower portion with a light oil or similar in order to prevent water take up. There were quite a few potential negatives to using a modern alternative. I will also get the standard stuff for my Europa when the time comes.

All the best

Berni
Title: Re: Padding between chassis and body
Post by: BDA on Tuesday,April 16, 2024, 01:32:00 PM
As Fotog said, r.d. enterprises has a kit. I went another route. I found a local rubber supplier and got 3/8” thick closed cell neoprene foam. They cut it off a “loaf.” I used the jute that came off my car as a pattern and glued it to the frame.
Title: Re: Padding between chassis and body
Post by: TurboFource on Tuesday,April 16, 2024, 05:52:55 PM
I bought closed cell neoprene off Amazon that had an adhesive backing to so it just cut, peel and stick.
Title: Re: Padding between chassis and body
Post by: gideon on Tuesday,April 16, 2024, 07:44:14 PM
There were quite a few potential negatives to using a modern alternative.

What potential negatives do you see?
Title: Re: Padding between chassis and body
Post by: buroz on Wednesday,April 17, 2024, 03:49:35 AM
Thanks for the replies.
FYI I'm based in the UK.

Neoprene - will this not hold the water? I'm thinking of a wet suit, but maybe there are different types of neoprene?
Title: Re: Padding between chassis and body
Post by: BDA on Wednesday,April 17, 2024, 04:44:03 AM
I’m not familiar with wet suits but I wouldn’t think they hold water or how would they dry out between dives? I don’t think closed cell neoprene will hold water. Certainly less than the original jute!
Title: Re: Padding between chassis and body
Post by: Kendo on Wednesday,April 17, 2024, 07:08:55 AM
Yes, a wetsuit is wet because water leaks around the wrist, ankle, and neck holes to contact the skin, not because the neoprene absorbs water. (I used to water ski in the winter)
Title: Re: Padding between chassis and body
Post by: buroz on Wednesday,April 17, 2024, 08:20:39 AM
"Wetsuits are made of a kind of rubber called neoprene. The suit traps a thin layer of water between the neoprene and the wearer's skin. So, the wearer is always wet—that's why it's called a wetsuit. Body heat warms the layer of trapped water and helps keep the wearer warm."

You are correct. I always thought the trapped water was in the neoprene... every day is a school day :)
Cool. I'll have a look at getting some neoprene. Thank you!  :)
Title: Re: Padding between chassis and body
Post by: Fotog on Wednesday,April 17, 2024, 09:20:03 AM
You know... not all neoprene is closed-cell foam.  You can  get it in solid sheets too.  About the foam:  I guess the thinking in an application like this is that solid rubber is too hard.  Is that right?  Nobody's said it, but why else use a foam?  In the case of wetsuits it's because of the insulating properties.  I don't believe that's what you're trying for here.

If the foam is too soft, of course it will totally compress and it will be as if no foam was used; just solid rubber. 

For reference, and since I could, I checked the tires on my Lotus for their hardness, and on the Shore A hardness scale, (typically used for elastomeric materials like rubber) I measured ~62.

On my wetsuit that I use for sailing, I measured 10.  This is a linear scale.  The measurements aren't exactly according to engineering standards (e.g. the neoprene foam is not .5" thick, and is nylon-covered), but the comparison is somewhat meaningful.

Hopefully this will confuse you about what to do.  :-)
Title: Re: Padding between chassis and body
Post by: BDA on Wednesday,April 17, 2024, 10:11:52 AM
My thought when I got the closed cell neoprene foam was to provide a similar a compressible cushion between the body and the frame that wouldn't deteriorate or hold water. Now that you mention hardness, I supposed foam comes in different hardesses just as solid rubber but I don't think that even came up when I bought mine. I suppose you could get solid rubber that was soft enough. I don't know. I would think that foam would likely be a lot softer than any solid rubber and you want something that compresses a little.

As with most cats, there are probably several ways for this one to be skinned. I'm happy with the the way my closed cell neoprene foam worked for me.
Title: Re: Padding between chassis and body
Post by: buroz on Wednesday,April 17, 2024, 10:28:00 AM
Hello BDA,
I have a roll of rubber matting left over from when we put it down in the back of our [carpeted] VW Transported, as we do a lot of mountain biking. I had considered using this, but I think neoprene would be better. Compress up and stop and vibration.
I take it you have it in a running car and it's doing the trick/working well?
Title: Re: Padding between chassis and body
Post by: berni29 on Wednesday,April 17, 2024, 10:30:14 AM
There were quite a few potential negatives to using a modern alternative.

What potential negatives do you see?

Hi

I was trawling the net for peoples experiences. Most of the negatives revolved around "NVH" from using neoprene or similar. I then looked up the chemical properties and expected lifespan of some of the different materials that people use (neoprene, other closed cell rubbers/foams, yoga mats for instance) and just came away feeling that the original felt was in fact the best compromise.

As they say YMMV!

All the best

Berni
Title: Re: Padding between chassis and body
Post by: Fotog on Wednesday,April 17, 2024, 10:34:22 AM
I checked the neoprene wetsuit again, attempting to double it up to get a proper half inch thickness. I measured about 4 on the Shore scale.

About cats:  I checked mine. He measures a zero, but he's pretty fuzzy.

FWIW!
Title: Re: Padding between chassis and body
Post by: BDA on Wednesday,April 17, 2024, 01:20:54 PM
Hello BDA,
I have a roll of rubber matting left over from when we put it down in the back of our [carpeted] VW Transported, as we do a lot of mountain biking. I had considered using this, but I think neoprene would be better. Compress up and stop and vibration.
I take it you have it in a running car and it's doing the trick/working well?
Yep for over 20 years (unfortunately not as many miles as 20 years should imply  :( ).