Thread: Front floor panels - seals or silastic

I use mastic for sealing the panels, silicon fractures and is a nightmare to remove for next time the panels come up.

The acme thread screws (very coarse thread) that hold the floor down are available from most LR suppliers.
4 Wheel Drives in Melbourne keep them (their Pn P13B at 75cents each)

My Series 2 had the passenger floor panel held down with Silicon sealant. Was a PITA to get the floor panel up, mastic is the best bet as already suggested.


Colin

What are we calling "mastic"? It's used to describe many things, from tile adhesive to tubes of Selleys "Butyl mastic" which I'd guess is closer to the product in question. But that would be very messy - it never sets so if the panels were removed it would need to be cleaned off with turps. It's also not recommended for use in thin layers, because in such use it can completely set and become brittle.

Has anyone ever tried self adhesive closed cell neoprene foam, similar to draught excluder strip? We used to use it to seal removable panels and it stopped leaks, dust ingression and rattles quite effectively.

Neoprene by nature is an open cell rubber. It's poured and "blown" with gas, anything from air for the cheap stuff to pure nitrogen or other exotics for the good stuff to improve it compression resistance and insulation. I wouldn't be using it as it's very prone to tearing a soft insertion rubber strip would be the go or you can get cured silicone sheeting that could be cut into the strips you require, then seal the corners with a small amount of silicone. Just punch the holes with a wad punch (no matter what rubber you use, unless it's heavy and can be drilled).

I have used self adhesive closed cell neoprene (from Clark Rubber) for many years now. Very effective, makes the panels easy to remove and seals well. Although there are still likely to be leaks in some of the corners where there is no panel lap (for example at the front corners of the seat box.

Yes, it tears easily - makes it dead easy to put the holes for the bolts.

The floor panels are held by Acme thread screws (large head except the ones round the boot for the hi-lo lever) into spring steel captive speednuts (both available from any of the usual suppliers) plus mudguard washers except at the outer edge and front edge onto the footwell. On the outer edge they are held by 1"x1/4"UNF galvanised or sherardised bolts with a mudguard washer on top and flat and spring washers on the bottom. The front edge is held by the same bolts and washers, but going into captive nuts in spot welded pockets on the outside of the footwell. Since these are exposed to road spray, they usually rust up and spin, destroying the pocket. Replace them with the Acme thread screws and speednuts. I don't know why this was not used in the first place.

John

Originally Posted by clubagreenie

Neoprene by nature is an open cell rubber. It's poured and "blown" with gas, anything from air for the cheap stuff to pure nitrogen or other exotics for the good stuff to improve it compression resistance and insulation. I wouldn't be using it as it's very prone to tearing a soft insertion rubber strip would be the go or you can get cured silicone sheeting that could be cut into the strips you require, then seal the corners with a small amount of silicone. Just punch the holes with a wad punch (no matter what rubber you use, unless it's heavy and can be drilled).

I believe neoprene comes in both open and closed cell varieties, certainly is is marketed as such. In any case, after years of using "closed cell" neoprene for seals and wetsuits, I have yet to find any significant water absorportion.

Yes it is prone to tearing, but when sandwiched between two pieces of aluminium there is little chance of it getting snagged on anything. The advantage of neoprene is that it will compress to minimal thickness when sandwiched between two tight fitting panels, but where the panels are not completely true it will fill the varying gap. And the panel can be removed and replaced with no mess, and still seals!

We also tried soft "solid" rubber, but it doesn't compress to the same degree (at least the products we tried didn't). The same applies to hollow silicon "tube" products which only compresses easily to (approximately) 2x wall thickness. Both work really well where there is a reasonably consistent gap where a seal thickness can be chosen to suit, but less well in tight-but-variable situations. We found they also worked best when the panels to be sealed were rigid, as the more solid seals tended to bow the panel between fasteners. On the other hand the neoprene strip would provide a reasonable weather seal between two pieces of GRP that were attached at metre spacings.

Neoprene for wetsuits is open cell. It doesn't refer to each cell being adjoined to the next but rather the fact that it has open bubbles as opposed to a closed cell type foam that is made up of something akin to bean bag beans crammed into a mould and compressed and heated to mate.

The open cell will not absorb water, only the exterior fabric layers will saturate, which is why an internally lined (terry like material) wetsuit is warmer than a smooth rubber lined. The material will wet out and if the suit fits correctly very little water transfer will take place so that once warmed by body temp. it will stay and not exchange.

The black carbon content rubbers that look and feel like neoprene (maybe a bit firmer) are nitrile rubbers. Closed cell, or more just a solid mass but with a lower duro rating.

When wetsuits are manufactured by hand (customs and made to measure) and the REALLY good off the shelfs the cutter is actually heated so it seals and makes a smooth edge surface for the glued butt joint. If the edge is just cut and left as a matrix of open cells the glue doesn't fill the surface completely and it leaks or worse just tears.

I've had suits that barely lasted a summer and I have a suit that's over 10 years old. There's no collapse of the foam and no rot or deterioration of the seams and it would have over 5000 hours in the water on it alone. And then there's the suits that last one day because they don't like contact with petrochem products.

I had a nitrile suit with built in boots and gloves, dry zipped and neck sealed and when combined with a superlite (there's a misnomer they weight about 18kg) dive hat it's completely dry and environmentally sealed. Chemical and even nuke proof with an oversuit.

how about compriband, available from hardware shops.
its a tar impregnated foam that when compressed enough can become gas tight.
also being tar will stick nicely.

i think from memory its either 12mm x 19mm or 25mm x 50mm and 2m long lengths in a pack of 2.
the shop i worked at would sell single lengths