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View Full Version : anti-freeze, sovlents, epoxy, rot and penetration!



paul oman
07-04-2003, 02:40 PM
Hello:

I know we keep going over this again and again. Just recently there was a long thread on this
topic. I like the comments about the glycol being attracted to the water/dampness while the
epoxy/solvents were not. I have been a big proponent of the 'anti-freeze' approach to wood rot
for several years. In that recent thread, I also noted that epoxy seemed to stick well to anti-freeze residue.

I've been doing some more testing and wanted to share my results and read everyone's comments!

I found that if I mixed 3 parts epoxy, 1 part solvent, and 1 part anti-freeze I got a 'product' that didn't
separate out into its three parts. I imagine this would make a good dry/wet rot fungus klller with good penetration. Sort
of the best of everyone's ideas??????

After two day I top coated the gummy and waxy end product with a layer of 100% solids epoxy, End result was still a bit gummy
and tacky but a suitable bond. Probably one more coat of epoxy on top of that and I might have a paintable top surface.

Anyway, any comments?

paul oman
www.epoxyproducts.com/marine.html (http://www.epoxyproducts.com/marine.html)

Wiley Baggins
07-04-2003, 05:04 PM
I've followed this "debate" with interest, but unlike you I have not generated any empirical data. It sounds to me as if you are building up layers of uncured materials, which I assume cannot be a good thing. Am I misreading your description?

thechemist
07-05-2003, 12:18 PM
Gellation of epoxy resin/curing agents into a polymer with volatiles entrained therein is not wise.

You should take your experiment and do some accelerated-aging of it, baking it in a forced-circulating-air-with-exhaust oven at about 150-200F, measuring weight loss by weighing at regular intervals.

Do this over a period of a few hundred hours, to get an idea of what happens with months to years outdoors in service.

You should study books or take a college course in polymer chemistry to learn some of the fundamental principles of the technology. What you are doing is not really good practice. The reason it is not good practice is that what you are making is unstable and will dramatically change its properties with time. Age it in your lab oven and you will see.

Frank Wentzel
07-06-2003, 01:24 AM
Chemist,

Could you suggest some books on polymer chemistry that might still be in print? I'd like to get educated on the subject but don't know where to start.

/// Frank ///

Dave Carnell
07-06-2003, 06:47 AM
Paul,

While your epoxy mixture containing EG is stable by itself, when it hits water in the wood, it will start to separate, as does CPES. The most effective use of glycol for killing rot is separate treatment where you get the full benefit of glycol's attraction to both water and cellulose. Then use the epoxy undiluted for solidification or gluing.

thechemist
07-06-2003, 03:52 PM
Originally posted by Frank Wentzel:
Chemist,

Could you suggest some books on polymer chemistry that might still be in print? I'd like to get educated on the subject but don't know where to start.

/// Frank ///The literature of the manufacturers of resins [Resolution, formerly Shell], Dow, etc. and literature of curing agent manufacturers [Air products, Reichold, etc. often list books as well as journal articles. good books are usually out-of-print, but can be had as used ones. handbook of adhesive bonding by cagle, handbook of adhesives by skeist, handbook of epoxy resins by lee and neville, paint handbook by weismantel are all books.....but current knowledge comes also from contemporary supliers of raw materials to the industry and their presentations at industry conferences. many of those papers are available as reprints from the material suppliers and are also published in monthly or weekly periodicals such as chemical marketing reporter, paint & coatings industry, modern plastics, research & development and others I don't recall at the moment. there is also a gread deal of the formulating art that is learned "on the bench" and passed along from senior formulating chemists to juniors. the manufacturers' sales reps that call on their customers are a wealth of information about almost anything. I have found some of the older, more exoerienced ones to be a wealth of useful information.

Dave Carnell
07-07-2003, 12:29 PM
The thixotropic effect of fumed silica on epoxy resins can be increased almost 10-fold by adding just a little ethylene glycol (antifreeze), about one tenth the amount of the silica; e.g. 0.3% glycol with 3% silica. Dow's "Formulating With Dow Epoxy Resin" says "The efficiency and viscosity stability of systems thickened with fumed silica can be improved through the addition of highly polar additives (a glycol-type material is best)." Their chemists, typically, chose triethylene glycol where an engineer would use the lowest cost most readily available compound, ethylene glycol. I confirmed about ten years ago that antifreeze does make Cab-O-SilŪ more effective.

Ethylene glycol is quite polar (like water) in the non-polar epoxy. Makes me wonder if maybe water itself might not do the trick. There's an experiment to try.

Popeye
07-07-2003, 01:14 PM
Everytime i picked up a technical manual, journal or other, i lost track of my original plan.. that was to do a trial and see (ie experiment). Possibly 80% of the science is wrong, and therein lies discovery and invention. why not try to solve the 'gummy' problem and keep going?

"Always listen to experts. They'll tell you what can't be done and why. Then do it".

-- Robert Heinlein

Wiley Baggins
07-07-2003, 05:04 PM
Originally posted by Dave Carnell:

<snip>The most effective use of glycol for killing rot is separate treatment where you get the full benefit of glycol's attraction to both water and cellulose. Then use the epoxy undiluted for solidification or gluing.<snip>Dave (and others),

This is more in keeping with what I imagine is a preferred approach. I wonder about the efficacy of EG as a preventative treatment when used in the manner described above. I am particularly interested in the benefits of such treatment versus (or in conjunction with) similar treatment with borate solutions.

Wayne Jeffers
07-07-2003, 08:46 PM
Wiley,

Have you seen Dave's home page? He has some information there on glycol and borates in fighting rot.

http://home.att.net/~DaveCarnell/

Wayne

Wiley Baggins
07-07-2003, 09:38 PM
Wayne,

Thanks, I had not looked at Dave's page for some time and had forgotten how much information was included (Thanks, Dave!). As a fan of the "belts and suspenders approach" espoused by Dave I have considered the EG and borates mix as worth applying between layers when cold molding. It strikes me as particularly cost effective insurance as long as it doesn't interfere with the adhesive (epoxy).

Dave Carnell
07-08-2003, 04:13 AM
I had so much trouble getting that page up that I haven't updated it. In the interim I have found that just the antifreeze is most effective usually. I wouldn't use borates on any wood that I want to glue up with epoxy or apply finish to. Too, Gougeon's research has shown that borates reduce the strength of glue bonds. It may well be because of the deposits they leave on the surface.

You are on your own, but I just stick with the antifreeze now.

RodB
07-08-2003, 04:53 AM
Let me get this straight, Dave. If you are doing new construction such as stitch and glue or cold molding, you could apply EG to the bare wood, let it dry for a few days, and then continue with glassing ... and the results would be encapsulated wood that also has a anti-fungal, anti-spore, anti-bacterial substance within the composite matrix. And this would make your "state of the art" wood construction be even more resistant to rot!!!???

All this plus being able to use EG on older construction with pre-existing rot problems?

This sounds like it might be worth trying (in new construction) in areas of the boat (like the bilge) where you expect moisture to be throughout the years.

How about soaking items such as toe rails, cabin sole planks, etc., with EG before coating with epoxy and varnishing?

Just some thoughts.

RB

Wiley Baggins
07-08-2003, 09:26 AM
Dave,

Thanks for the update. Given EG's affinity for water and the (modest) permeability of most coatings (read "paint") and the epoxy glue lines I assume that there would be some leaching out over time, but that the benefits would outweigh the slow reduction in protection.

Based on your comments about borates and glue lines perhaps the best approach is the use of EG between the layers of cold molding and borates on interior surfaces.

Thoughts?

paul oman
07-08-2003, 09:34 AM
this is great! Exactly the kind of thread I wanted to get going - lots of ideas and questiions. What about heating the surface and/or the anti freeze with a heat lamp to aid penetration, etc. and then perhaps speed the evaporation of the anti-freeze so that an epoxy topcoat (or some other putty, paint, etc) could be applied sooner and perhaps with a better bond?

Note: I am starting to believe that heated surfaces are the best way to aid in epoxy penetration.- perhaps the same with the anti-freeze?

paul oman
www.epoxyproducts.com/marine.html (http://www.epoxyproducts.com/marine.html)

Wayne Jeffers
07-08-2003, 09:56 AM
Wiley,

My thoughts:

What kind of boat are you thinking of cold molding? Where will you keep it? What kind of wood do you plan to use?

Answers to these questions may suggest the answer to the question of use of EG.

If you're using a rot resistant species, such as western red cedar, in cold molding I wonder whether applying EG may add little additional rot resistance. Perhaps so little additional rot resistance as to not be worth the trouble, expense, and (perhaps slight) chance that it may interfere with the epoxy bond. A less rot resistant wood species in cold molding may make a more compelling argument for application of EG to inhibit rot.

If it's an open boat which will be dry sailed and stored out of the weather, EG may not be worth the trouble, etc. But if it will have compartments or ceiling where portions of the hull are substantially inaccessible, of if it will be left on a mooring, or out in the weather, the argument for additional rot protection becomes stronger.

I find Dave's case for EG very persuasive, especially for Douglas fir or Southern pine plywood or for boats with a workboat-quality finish. But I'd personally like to see more empirical data supporting the benefits and demonstrating non-interference with epoxy glue before using it on western red cedar veneers prior to cold-molding a boat that I intended to become a showpiece.

Wayne

Popeye
07-08-2003, 09:57 AM
does this suggest a cca pressure treated lumber approach? other variables are wood species, temp, time of contact, etc, etc.

can small molecules and thin, gummy, polymers migrate and reside happily; deep, deep into wood pores?

"The best way to have a good idea is to have a lot of ideas."

--Linus Pauling