Monday, March 2, 2009

I like shiny things

Before I went off and had a few centimeters of my manliness removed, I got some work done on my bar. I made it all real nice and shiny. In addition to the obvious use of polyurethane, I coated the surface of the bar with a substance known as Envirotex.

Envirotex is a resin that can be poured onto a surface resulting in a shiny and resilient surface. There are two solutions, the resin and the hardener. These are mixed in a 50:50 ratio and stirred like mad.

The chemistry is bit complicated due to the number of components, but the net result is the formation of a polymer between bisphenol A and epichlorohydrin.
The first step is to seal the wood to prevent air from forming bubbles in the resin. I coated the wood with 2 coats of polyurethane. The second step was to fill in the gaps between the trim. I was going to flood coat the top of the bar using the trim as a dam to keep it contained, but if the cracks (small as they might be) were not plugged the resin would leak out. I filled them up with a small amount of Envirotex.
Here are a few pics. You can kind of see where I did and didn't add the resin.


When that cured I flooded the whole top. Here's the result. The draft tower shown has not been installed yet. That comes next.



Progress. Glacial, but steady.

10 comments:

milkshake said...

I am sorry but your epoxy chemistry is incomplete. There is no free epichlorohydrine in the epoxy resin, and for good reason because epichlorohydrine is a volatile and super-genotoxic carcinogen, and you need a base when you condense it with phenols as you depicted, by ring openning+ ring closing of the product. What they do in the plant is to manufacture a bisphenol/epichlorohydrine oligomer that has terminal epoxides (as you have shown), and thats the one part of the binary. The second part, the cross-linking agent, is typically a diamine like ethylene diamine or diethylene triamine, xylenediamine or isophoron diamine for slow-hardening high-strenght epoxy resins. The problem with some strongly-basic polyamines is that the produced resin is yellowish and the amine can also cause dark discoloration of wood. Other hardeners include piperazine, imidazolones and 2,4,6-tris (dimethylaminomethyl)phenol.

katiedid said...

Whoa, very pretty!

Chemgeek said...

Milkshake- you are indeed correct. I over-simplified the chemistry in an attempt to make it less complex and due to ignorance. The hardener contains the base. It is 5% N-aminoethylpiperazine, 40% polyoxyalkyleneamines and 55% nonyl phenol. It smells of fish. I'm not exactly sure what the role of the nonyl phenol is, but I assume it is a solvent/reactant.

milkshake said...

I think nonyl phenol is there as a plasticizer but maybe serves as a chain-terminating agent also. Some old-formula epoxy hardeners come diluted with benzyl alcohol.

Tony T. said...

Very shiny; it looks great. Are you not worried about toxicity with Bisphenol A, though? I know the FDA is okay with it, but a lot of other groups are not. You're a chemist, and I'm not; what are your thoughts?

Chemgeek said...

Tony,

Nope. Once it is polymerized it is harmless.

Bricks can be used as weapons, but once they are part of a wall they have been rendered non-weaponious. Just like monomers and polymers.

Lisa-tastrophies said...

I would like to reserve a barstool of one please. And do you give teacher discounts?

Chemgeek said...

Lisa- Teachers drink free... for as long as is necessary.

Taitauwai said...

So shinny... nice work!

travis said...

I don't know much about chemistry, but I love beer. That bar top is a truly worthy beer distributing surface.