Need help finding a certain kind of foam

  • Thread starter Thread starter leroyjenkens
  • Start date Start date
Click For Summary

Discussion Overview

The discussion revolves around finding a suitable type of foam that can be used as an airtight seal, specifically for a vacuum chamber application. Participants explore various foam types, their properties, and alternative materials that may fulfill the requirements.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant seeks a soft, closed cell foam that can serve as an airtight seal, expressing uncertainty about specific foam types and names.
  • Several participants inquire about the chemical resistance, durability, and UV exposure of the foam, suggesting these factors may influence the choice.
  • Another participant mentions using spray foam for seals and suggests checking hobby stores or upholsterers for foam options.
  • Some participants propose alternatives to foam, such as neoprene and Teflon, questioning the necessity of using foam for the sealing application.
  • One participant notes that neoprene is soft and durable, suggesting it might be suitable, while another mentions the potential for softer versions of neoprene.
  • Participants discuss the possibility of using silicone sealants, acknowledging their messiness but noting their softness.
  • Links to various foam suppliers are shared, indicating potential sources for purchasing foam online.
  • Concerns are raised about the effectiveness of foam in high vacuum environments, with one participant asserting that foamed seals may not achieve the necessary pressures.

Areas of Agreement / Disagreement

Participants express differing opinions on the suitability of foam for vacuum sealing, with some advocating for foam and others suggesting alternative materials. The discussion remains unresolved regarding the best material for the specific application.

Contextual Notes

Participants highlight the importance of specific use cases, such as exposure to chemicals and UV light, which may affect the choice of foam. The discussion also reflects uncertainty about the effectiveness of foamed seals in high vacuum conditions.

leroyjenkens
Messages
621
Reaction score
49
I'm looking for some foam that can be used as an airtight seal, but it needs to be soft. Maybe a little bit firmer than memory foam, if you know how soft that is. So it needs to be closed cell foam, that's relatively soft, but I don't know what kind of foam to search for. I'd have to buy it online because I don't know of any stores that specialize in foam. I just don't know what kind of foam to look for. I don't know any of the names. Anyone have any suggestions?
 
Engineering news on Phys.org
Does it have to be chemically resistant? How long does it have to last? Will it be exposed to sunlight or UV?
 
leroyjenkens said:
I'm looking for some foam that can be used as an airtight seal, but it needs to be soft. Maybe a little bit firmer than memory foam, if you know how soft that is. So it needs to be closed cell foam, that's relatively soft, but I don't know what kind of foam to search for. I'd have to buy it online because I don't know of any stores that specialize in foam. I just don't know what kind of foam to look for. I don't know any of the names. Anyone have any suggestions?
What do you plan to use it for? That might help us find what you need. I use a spray foam to create seals around certain things. Hobby stores sell various types of foam in many textures and sizes. An upholsterer could sell you foam. Like I said...more info please.
 
lisab said:
Does it have to be chemically resistant? How long does it have to last? Will it be exposed to sunlight or UV?

No it doesn't have to resist chemicals and it's not going to be exposed to UV light.
What do you plan to use it for? That might help us find what you need. I use a spray foam to create seals around certain things. Hobby stores sell various types of foam in many textures and sizes. An upholsterer could sell you foam. Like I said...more info please.
It's going to be a seal for a vacuum chamber. I don't want it permanently stuck to the table, though.

I could check a hobby store. Then I could actually feel the foam to make sure it's what I want. Thanks.
I'll have to search for upholsterers.
 
Leroy, is there any particular reason that this has to be foam? I ask because most of the seals that I've seen in similar roles were neoprene, Teflon, etc..
 
Danger said:
Leroy, is there any particular reason that this has to be foam? I ask because most of the seals that I've seen in similar roles were neoprene, Teflon, etc..

I figured foam would provide the softness I wanted.

I have some neoprene, but it's kinda hard. It's like foam rubber. Is there a softer version of it?
 
leroyjenkens said:
Is there a softer version of it?

I don't know, but I think that the formula is reasonably alterable. There is also, of course, silicone sealant such as Imperial or DuPonte, or bathtub caulking. They're fairly soft. They're also messy as hell before they're dry, so might be more trouble than they're worth.
 
Neoprene is what SCUBA suits are made of. It's pretty soft, durable, and it's closed foam. Maybe a dive shop might have some they use as patches?
 
It might be worth a phonecall or email to a manufcturer. If you can reach a sales engineer they'll generally point you to a commercial otc product.

I found a few with a search...

http://www.clarkfoam.net/polyurethane_foam_products.html
http://canada.foambymail.com/polyurethane-foam.html
http://www.foamfabmn.com/polyurethane.html
http://www.generalplastics.com/?_vs...ign=General+Plastics&ex=ccfxuh-13c8k9q-dm09nf

also check your local auto parts store ... there's lots of gasket making plastic goop in tubes.

and boat supplies. Closed cell polyurethane is used for floatation because it doesn't soak up water.
 
Last edited by a moderator:
  • #10
  • #11
leroyjenkens said:
It's going to be a seal for a vacuum chamber. I don't want it permanently stuck to the table, though.

If you are going to use it for a high vacuum chamber, you will be very disappointed with foam of any kind. You will never get the pressures you need. High vacuum chambers use soft metal (zero outgassing) seals. You might get by with a solid silicone seal, though.

I wouldn't consider any kind of foamed seal in a vacuum environment.
 

Similar threads

Query regarding foam mattress 'shaking phenomenon'
  • · Replies 3 ·
Replies
3
Views
3K
Explosive Problem: Frozen Pipe in Basement Wall
  • · Replies 6 ·
Replies
6
Views
3K
Help needed with Polarisation (Rotated Waveplates)
  • · Replies 8 ·
Replies
8
Views
3K
Looking for a low-latency force-based actuator - do they exist?
  • · Replies 6 ·
Replies
6
Views
2K
Temperature, humidity and gas sealed box
  • · Replies 1 ·
Replies
1
Views
2K
Little strange material to find or build
  • · Replies 4 ·
Replies
4
Views
3K
Misc. Finding "Stuff": Surfing for Unknowns with Element13
  • · Replies 4 ·
Replies
4
Views
2K
How long will a hard Nylon cane last?
  • · Replies 26 ·
Replies
26
Views
3K
High-energy LC oscillatory discharge: what kind of switch?
  • · Replies 19 ·
Replies
19
Views
2K
Need advice and hints for working with helium
  • · Replies 14 ·
Replies
14
Views
2K