Silicone coating of Dyneema floors??

You would have to find coatings that adhere to mylar, a kind of polyester film or plastic sheet. Sounds like it will be a lot more trouble and less effective than just using a polycryo sheet underneath the DCF floor.  Or, buy a Notch inner with a silnylon floor.

I’ve sealed DCF shelters with Silnet and that worked well. Both Seek Outside and Zpacks say it’s fine to use silicone sealants on DCF if memory serves. Not sure why diluting with mineral spirits would lead to a very different result. Maybe try it on a small, unimportant area of DCF like on a stuff sack?

Yeah sure sealing okay but the OP wants to use silicone to try to make the mylar more puncture resistant.

Yes, good point. I did gather that from the OP, but I read the query as asking about the feasibility of using the technique more than anticipating the efficacy of the outcome.

possibly make it more resistant to puncture

(Emphasis in original)

if you don’t dilute the silicone it’s almost impossible to get a thin, uniform coat

I’ve coated nylon before that didn’t work very good.  After a while it started peeling off.  But it didn’t hurt the functionality of the nylon.  I think this might be a problem with the DCF.  Worst case, it’ll just peel off but it won’t degrade the DCF.  Maybe just do a small area first – where it will get the most wear, like in the middle of the floor or under where you’d sleep.

I’m skeptical that a thin silicone coating would provide puncture resistance, but that’s not the question being asked here : )

…it didn’t hurt the functionality of the nylon. I think this might be a problem with the DCF. Worst case, it’ll just peel off but it won’t degrade the DCF.  (Emphasis added.)

So isn’t the worst case that it peels off and degrades the DCF?

yeah, peeling off and degrading the DCF would be worse : )

I don’t see the point of this. If DCF gets punctured, it’s the easiest fabric to repair in the field.
If you know you’ll be camping where punctures are likely, taking a sheet of polycryo or window plastic is the only serious answer.
The only scenario in which this kind of treatment might possibly make any sense is when the inevitable micro holes in the DCF due to extended use begin to effect waterproofness.

Silicone coating on DCF would be a good solution once the material has already started to become abraded and “fuzzy” as is common over time with DCF “fabric” for such applications that induce friction/abrasion.

This provides greater surface area and “toothy/jagged” structure for the silicone adhesive to “grab onto” so to speak.

Silicone coating can save, or rather prolong, the life of aged DCF.  But you must clean it very well with a solvent first.

I don’t think silicone will adhere well to new DCF.  Mylar/PET has moderately low surface energy–lower than even nylon/polyamides.

In composites, gluing, and bonding arenas, one of common techniques for proper bonding is to rough up the surface of the materials to be bonded, especially when the material is not one that is readily strongly bonded in its natural state.  Similar principle applies here with DCF and silicone.

Also, I don’t know how much penetration resistance it will add to DCF.  One of the reasons why silicone coating adds tear (especially) and a bit of tensile strength to woven nylon and polyester fabrics while PU tends to reduce these (especially tear), is because silicone is more rubbery and slippery in nature and it flexes/moves with the fibers and while it provides somewhat of a “holding matrix” for the fibers, it doesn’t “lock them into place” like PU does more so.  It’s sort of the old flexible willow vs hard, more brittle oak in wind analogy.

That property of PU that isn’t good for tear resistance, might actually be better for penetration resistance?   Not completely sure one way or another.  But something to consider, think about, and/or research more in depth.