I may have found some bio resistant paint.

[Julian]

I recently finished laying my own version of Tiananmen square at the back of the house, finally covering my PLUG.  Where I carry oil over it to get to the shed, the slightest drip of oil showed very clearly so, in an attempt to prevent this and to try and retain the colour of the stone, I bought some sealer, this stuff ... http://www.adseal.info/Adseal-Heavy-Duty.html

I applied it yesterday and I have to say it's looking to be excellent stuff.  Goes on really easily and soaks into the stone forming an elastic skin that's become harder and less elastic over night.  A test on a piece of scrap stone applied about a week ago, allows bio to be wiped off with no noticeable effect.  I've set up some test pieces and will post more results if things look promising.

It's not cheap, but it gives good coverage and can be had in 5 ltr tins ... could be good for bunding. as well as floors.

[willbuild]

Normally these sealants are silicon based. Is the same as what we use for injectable damp proof coarse. you can buy 25ltrs for around £30 to £40 from hire shops.
Dont have any left over from any jobs, but am def going to try.

[Julian]

Now that Tiananmen square has been rained on, it certainly looks like it contains something similar to silicone, the water forming large droplets and certainly not being absorbed.  Walking over the wet surface in trainers produces disconcertingly loud squeaking noises (unintentionally invitation for comment there). However, t these are the ingredients from the MSDS ...

2. COMPOSITION / INFORMATION ON INGREDIENTS
CONTAINING: XYLENE

dimethyl-benzene

Acrylate 10 - 30%
2-methylbenzene 70 - 100%


I assume the plastic/resin bit is the acrylate and the 2-methylbenzene is the carrier.  Not sure where the xylene and dimethyl-benzene come in.

Looking at the way it took to the paving and it's viscosity, I'd be surprised if it's exactly the same as damp proofing liquid.

I peeled some "skin" off the roller tray before it dried completely and that's been sat in some bio all day with no noticeable effect.  Being so thin if it was effected you'd expect it to show up pretty quickly.

On the test piece of paving the bio isn't showing any ill effects nor is veg oil,  Methanol did effect it quite badly turning the surface white, but then they do state it's effected by most solvents.

[willbuild]

I found some natural stone sealant and it contains silicate. Ive coated a sample of mdf and ply. See what is like when dry.
Most dpc fluids and brick sealants are silicates but a few are not (they tend to be the expensive ones)

[Julian]

MDF ... good idea!

I've just glued up a little box which, when dry, I'll paint with a couple of coats of this stuff and see how it holds up.

[Julian]

Well, so far so good ...





It's had three coats of the sealer.  The "wet" looking bits around the joints are stray glue, not escaping bio!

[Julian]

I sent the MSDS to a friend who used to work for a subsidiary of a well known chemical company making paints.

This was the reply ...

=================

Data sheet shows that it is an Acrylate in Xylene.  Xylene (dimethyl benzene) is just the carrier (solvent) and all the hazard warnings relate to the xylene, not the acrylate.

Acrylate is a generic term for all polymers with an acrylate group (CH2:CHCO2).  Most typically these are used in coatings eg Ethyl Acrylate (soft & flexible) to Methyl Methacrylate (hard & brittle). I guess yours is somewhere in between - not too brittle but not soft & sticky.

==================

Not sure it helps much as we can't tell which acrylate it is, but no silicones.

[Julian]

Interesting and completely inconclusive!

Went and had a look at my little box (waits for incoming remarks) and this is the current state ...



Although the sides seem to be soaked in bio, the bottom isn't and there was none on the bench.  I think the most likely scenario is that it's "crept" up the sides, over the top edges (which were painted) and soaked into the outside of the sides.  It's been prevented from soaking into the bottom by the glue.

Perhaps PVA wood glue is the "magic" paint ... I give up!

[julesandtash]

Maybe you need another test box but with a timelapse camera on it (a webcam would do with scheduled image capture every 10 minutes or so)
Then you could see what happened over time

[Julian]

Another box?  Do you know how difficult that one was to make?

[Julian]

After five days, the box still looks the same, the bottom shows no signs of contamination.

So I recon it's probably fair to say that this stuff is bio proof and could be used for bunds etc.  So the construction could be brick or block with a flush surface or rendering or wood with something like calking round the joints.

[Julian]

Still the same!

[Julian]

Still the same but all the bio's gone!  Assume it's all soaked into the sides, so I've filled it with water ... just seemed like a good idea at the time!