Urethane or Softer Material Question

[Greg Guimond]

I need a material that will stand up to marine use and act as an insert to stop gel coat or paint from abrasion and scratching over time. It would need to sit inside a channel and would probably be attached by epoxy. Any ideas would be appreciated. Attached is a profile of the channel.

[realbold]

Neoprene comes in different hardnesses called durometer.
(40 durometer being softer, 80 harder)

[Bamboo Loui]

Greg-- no promises, but I have worked in urethanes most of my working life. I am not sure I understand what you are looking for. Could you be a little more descriptive?
or you can PM me if you wish.

Doug

[joseph m. hahnl]

I need a material that will stand up to marine use and act as an insert to stop gel coat or paint from abrasion and scratching over time. It would need to sit inside a channel and would probably be attached by epoxy. Any ideas would be appreciated. Attached is a profile of the channel.

Use: UHMW High impact plastic

http://www.ptreeusa.com/uhmwproducts.htm

[Bamboo Loui]

Hi Greg-- while I like neoprene, and I use allot of UHMW at work and at home, I am wondering if you are looking for something that will act as a gasket? or a cushion?
A gasket could be made out of numerous materials. I like silicones, silicone rubbers for their chemical resistance and softness. Urethanes are good too but there are both poly [ethers] and poly [esters]. Ethers are better around water and esters are better around solvents. Silicones and the polyethylene of the UHMW are pretty inert and can withstand both water and solvents pretty good depending on blend.
If you are looking for some cushion and compliance, I like expanded polyethylene--- looks like polystyrene but has way more cushion and will not break apart like a polystyrene coffee cup. BUT-- PE does not like glue nor does expanded Polypropylene (PP has less cushion but is weight supportive than PE)

If this is not permanently attached I wonder about soft materials of any kind getting dirty or getting sand embedded in the materials and then the sand or dirt will be the abrader. If is not permanently attached, I would want to be able to clean it regularly--

There is one other thing I was thinking too-- again depending on the cushion or gasket- but could be a compromise-- we often use and design silicone hollow extrusions for cushion/gasket/seals for some of our equipment. It is soft-- would pick up dirt eventually, but could be cleaned-- think of a soft hose.


I'm still thinking-- help me more with direction:wink:

Doug

[Greg Guimond]

Bamboo, thanks for the thoughts. No gasket required it would only act as a cushion. Ideally it would be mechanically attached at both locations depending on the material chosen. The reason I would prefer a mechanical countersunk attach method is that you could easily replace the "cushions" if they became dirty to your point. Last point is there would be (2) of these cushions and they would need to be about two feet long give or take.

[Bamboo Loui]

I like that pic--

for the heck of it I went on line and found this site as an example. I never have worked with them but use it for informational purposes. they have some neat stuff like the Volara? and their open cell "dry Foam"
http://www.closedcellfoams.com/sitemap.html (http://www.closedcellfoams.com/sitemap.html)

I may have some material at the plant and will take a look tomorrow afternoon. I might also have a silicone extrusion or two and can send a drawing of the cross sections to you.
You could fabric wrap or Vinyl wrap the materials-- Vinyl and fabrics will glue or respond to mechanical attachment methods and you can clean it as you you know from your seats. The closed cell foams will keep the cushion properties longer than the open cell foams if they are going to get wet and you cannot dry them out-- other wise open is ok as long as you can dry it.
If you decide on Polyurethane, I think the Ether would suit you best even though you are close to the solvent vapors from the fuels and oils.

[Greg Guimond]

Appreciate all the input! I thought about Delrin as well. The product will not have any exposure to solvents, only salt air, soap and water, and the waxes that would keep the hull clean per normal use when the rumble hatch is open or removed completely. :wink:

[joseph m. hahnl]

Appreciate all the input! I thought about Delrin as well. The product will not have any exposure to solvents, only salt air, soap and water, and the waxes that would keep the hull clean per normal use when the rumble hatch is open or removed completely. :wink:

Teflon is another plastic that you can use. Teflon is slippery than (Edit).
Teflon also does not change shape or size with heat and cold.

this will explain more http://www.lenntech.com/teflon.htm

[MOP]

Another possibility is using the soft side of Velcro self stick, I have used it as a cushioning wear strip on several items. If and when it gets worn just pull it off and put new in its place, pretty simple will fit almost any shape and stick well to any clean smooth surface.

Phil