[Cob] report on earthen floor, 14 months in

[Shannon Dealy]

[snip]
> However, what I see in my kitchen (where most of the action is) is a floor
> that is NOT hard enough.  The wooden kitchen chairs, when someone sits in
> them (and, surprise, that happens a lot) will leave (permanent) dents in the
> floor, deep enough for a quarter to sit in.   I?ve dropped some things, and
> they?ve left noticeable dings.   Basically, it?s not hard enough.  That?s
> pretty frustrating, as I don?t know how I can repair it.
[snip]

It is not clear from your description what "100% oil" is (type of oil, 
boiled/raw, additives included in the base oil, etc.).  In any case, you 
may be experiencing something that happened to me years ago when I did a 
floor in a hurry (I was leaving the country for a long period and short on 
time).  I applied lots of coats (boiled linseed oil, no solvent added 
by me, but it generally has a fair bit of solvent in it already) in a 
short period of time and cooked the floor in between coats using in floor 
heating at high temperature.  The resulting floor was quite solid so I 
cut the heat and moved things into the room a couple days later.  The only 
problem was that two days later the floor was soft again.  Ultimately, I 
realized that the oil in the floor hadn't hardened, only the surface had 
and it sealed the top trapping the solvent in the oil below.  Once the 
heat was removed, the solvent in the oil below softened the surface in 
the two days between when I cut the heat and started moving things 
in.

Ultimately, all the table legs left dents in the floor (not a big deal as 
this was my workshop building) and it took quite some time before it was 
really solid, at least a year, probably longer as I could still 
detect a faint smell of linseed oil over a year later.

While you didn't mention the heating thing I did, you may have created 
similar conditions by putting on so much oil without giving it time to 
harden between coats.

A simple demonstration of this is to take a large drop of linseed oil,
leave it on an impermeable surface and let it dry for a couple of weeks 
in a cool place (not in the sun).  The outside will be solid but flexible 
and the inside will be liquid.  This is essentially what happens when you 
leave linseed oil puddled on your floor rather than removing the excess.

FWIW.

Shannon C. Dealy      |               DeaTech Research Inc.
dealy at deatech.com     |          - Custom Software Development -
Phone: (800) 467-5820 |          - Natural Building Instruction -
    or: (541) 929-4089 |                  www.deatech.com