Are there any good cheap epoxy resins?

[Texas-Tri]

I’m looking to do some fiberglass work on the cheap. I am rebuilding an old trimaran and will be making some structural components for the cabin and deck probably with marine plywood coated in epoxied glass. I am new to this and I think that the general consensus is that West systems epoxies are the best and the industry standard, however they are not inexpensive. Has anyone had good luck working with any of the less expensive epoxy resins? For instance MAX BOND LV A/B is available on Ebay for about $40 per gallon. I’m hoping that someone has tried other (re: cheaper) epoxies and might be able to share your experiences. Thanks!

[mydauphin]

I buy some at $32 a gallons. However, I limit their uses to reinforcing and non structural components. Still it saves me lots of money. I mix it with different compounds and make fillers and glue out of it.

But definitely cheap epoxy is better than good polyester.

[tuantom]

I used US Composites epoxy for my boat project at under $50 for 1 and 1/3 gallons. I'm pretty happy with both the epoxy and their cloth prices.

[sbklf]

Originally Posted by mydauphin

I buy some at $32 a gallons. However, I limit their uses to reinforcing and non structural components. Still it saves me lots of money. I mix it with different compounds and make fillers and glue out of it.

But definitely cheap epoxy is better than good polyester.

Where can I purchase this epoxy your speaking of?

[nero]

US.composits epoxy is Epon Resin. If you are buying by the barrel then go direct. It will drop the price to around $26 a gallon. Some of the Epon resins are available in smaller amounts. Not sure which ones.

Also selection of an Epon Resin (there are 100's of them) is a bit involved.

US composists was my supplier at first. The shipping costs have become as much as the epoxy costs.

[mydauphin]

I am in Miami, Florida. And I can buy epoxy at $30 a gallon, or should I say $60 for a two gallon at a local supplier. I dont buy in larger quantity because I dont get much of a discount. I am also looking at new suppliers myself. But problem is shipping. These containers are not very sturdy and I think they consider epoxy a hazardous waste so I don't think it can be sent via regular ups.

[nero]

epoxy is not classified as a hazardous material or hazardous waste.

Forgot to note that Epon is based in Houston. Maybe you can find a local distributor.

[fhrussell]

Not quite as affordable as others listed here, but I've used this epoxy with great results.

http://www.jgreer.com/index.htm

[Boston]

you are right
plastics ( including epoxies ) are not presently classified as toxic
however virtually all the research being done on plastics
and there is a LOT of research in this area
is clearly showing otherwise

Both epichlorohydrin and bisphenol-A are endocrine disruptor's.
both are prevalent components in epoxies
the later being associated with genital malformations and reproductive and immune system disruption and mental disorders

respectfully I would cite the following articles
these are open access publications
so there is no issues with reproducing portions of them here

Graciela Ramilo1, Iago Valverde1, Jorge Lago1, Juan M. Vieites1 and Ana G. Cabado1

(1) Microbiology and Biotoxins Area, ANFACO-CECOPESCA, Campus Univ de Vigo, 36310 Vigo (Pontevedra), Spain
Received: 21 March 2006 Accepted: 17 May 2006 Published online: 17 June 2006

Abstract Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) are used as starting substances for the manufacturing of epoxy resins used in internal can coatings. They are obtained by a condensation reaction between epichlorohydrin with bisphenol A and bisphenol F, respectively. These potential endocrine disrupting chemicals are able to enter the food chain and to reach the intestinal epithelium, causing structural and functional damages. The human colorectal adenocarcinoma cell line Caco-2 is a widely used in vitro model of the intestinal cells. The aim of this study was to characterize BADGE and BFDGE toxicity in Caco-2 cells, in particular, at the cellular and molecular level. Using several approaches, we characterized BADGE- and BFDGE-induced cell toxicity in Caco-2 cells. The treatment was done using different concentrations up to cytotoxic doses and different times of exposure to the agents. We evaluated the effect of these compounds on cell morphology, cell detachment, cell proliferation, F-actin disruption and plasma membrane integrity. Both compounds are able to induce morphological changes, cell detachment from the substratum and to inhibit cell proliferation, being these effects time and dose-dependent. Moreover, BADGE and BFDGE induce F-actin depolymerization, this effect is very potent at 24 h of incubation with the agents and a complete F-actin disruption can be observed at 200 μM BADGE or BFDGE. In addition, cell integrity is not damaged, since neither propidium iodide uptake nor LDH release takes place in Caco-2 cells exposed to high doses of these agents for 24 h.

also

http://schizophreniabulletin.oxfordj...sc/terms.shtml


In recent years, numerous substances have been identified as so-called "endocrine disruptors" because exposure to them results in disruption of normal endocrine function with possible adverse health outcomes. The pathologic and behavioral abnormalities attributed to exposure to endocrine disruptors like bisphenol-A (BPA) have been studied in animals. Mental conditions ranging from cognitive impairment to autism have been linked to BPA exposure by more than one investigation. Concurrent with these developments in BPA research, schizophrenia research has continued to find evidence of possible endocrine or neuroendocrine involvement in the disease. Sufficient information now exists for a comparison of the neurotoxicological and behavioral pathology associated with exposure to BPA and other endocrine disruptors to the abnormalities observed in schizophrenia. This review summarizes these findings and proposes a theory of endocrine disruption, like that observed from BPA exposure, as a pathway of schizophrenia pathogenesis. The review shows similarities exist between the effects of exposure to BPA and other related chemicals with schizophrenia. These similarities can be observed in 11 broad categories of abnormality: physical development, brain anatomy, cellular anatomy, hormone function, neurotransmitters and receptors, proteins and factors, processes and substances, immunology, sexual development, social behaviors or physiological responses, and other behaviors. Some of these similarities are sexually dimorphic and support theories that sexual dimorphisms may be important to schizophrenia pathogenesis. Research recommendations for further elaboration of the theory are proposed.

I would also cite

The estrogenicity of bisphenol A-related diphenylalkanes with various substituents at the central carbon and the hydroxy groups.
P Perez, R Pulgar, F Olea-Serrano, M Villalobos, A Rivas, M Metzler, V Pedraza, and N Olea
Laboratory of Medical Investigation, Department of Radiology, School of Medicine, HUSC-University of Granada, Granada, Spain.
See letter "Bisphenol A diglycidyl ether as a potential metabolic source of bisphenol A." on page A472b.
This article has been cited by other articles in PMC.
Abstract
The chemical structure of hydroxylated diphenylalkanes or bisphenols consists of two phenolic rings joined together through a bridging carbon. This class of endocrine disruptors that mimic estrogens is widely used in industry, particularly in plastics. Bisphenol F, bisphenol A, fluorine-containing bisphenol A (bisphenol AF), and other diphenylalkanes were found to be estrogenic in a bioassay with MCF7 human breast cancer cells in culture (E-SCREEN assay). Bisphenols promoted cell proliferation and increased the synthesis and secretion of cell type-specific proteins. When ranked by proliferative potency, the longer the alkyl substituent at the bridging carbon, the lower the concentration needed for maximal cell yield; the most active compound contained two propyl chains at the bridging carbon. Bisphenols with two hydroxyl groups in the para position and an angular configuration are suitable for appropriate hydrogen bonding to the acceptor site of the estrogen receptor. Our data suggest that estrogenicity is influenced not only by the length of the substituents at the bridging carbon but also by their nature. Because diphenylalkane derivatives are widespread and their production and use are increasing, potential exposure of humans to estrogenic bisphenols is becoming a significant issue. The hazardous effects of inadvertent exposure to bisphenol-releasing chemicals in professional workers and the general populations therefore deserve investigation.

[JRL]

Originally Posted by tuantom

I used US Composites epoxy for my boat project at under $50 for 1 and 1/3 gallons. I'm pretty happy with both the epoxy and their cloth prices.

US composites stuff is cheap, but good!

Ive built several moulds. Made my own tooling surface coats. Also had decent luck making my own tooling clay using their resin.

[rwatson]

Originally Posted by Boston

you are right
plastics ( including epoxies ) are not presently classified as toxic
however virtually all the research being done on plastics
and there is a LOT of research in this area
is clearly showing otherwise

Bugger!!!!!! Looks like Aluminium *is* God.

[Boston]

lmao
well now ya know wood floats
plastic only floats half the time
aluminum
pretty sure that stuff sinks :-)

besides

wood has an embodied energy of about 640 kw/ ton
plastic 6x that of wood
steal 14x
aluminum 126x

now there are a lot of ways you can figure embodied energy
so whatever source you use for the numbers
are different than the next
but similar ratios are derived from whatever method you use
soooooooooo
you can hug a tree and build all the wood boats you want
or
you can run over some bunnies till you run out of aluminum
now I ask you
what would Budda do

[rwatson]

Ah yes Boston - embodied energy. But thats not the full story. Lets throw some "off the cuff" figures in the air ...

Lets say -
wooden boat, working life average 10 years without maintenance. (I just cant stress how much maintance repainting, repairing, varnishing, glueing goes on in the life of a well maintained wooden boat - all with petroleum based materials.)

Plastic - working life average 25 years with no maintenace. Sure fibreglass will last a lot longer with care, but lets say its a hard working boat. Once again, all petroleum products.

Aluminium - 35 years with no maintenance. I would say on average aluminium boats would be expected to last 3 times wood with no maintenance. And it comes from red dirt - not oil! (The most common solid element in the universe, let alone the world)

So, over a working life - overall energy spent is a lot less than the energy to produce initially.

Now, all the boats sink!
Does the aluminium boat get left to rot in the mangroves?
Nooooo - it gets recycled because it has great resale/recycle value and the next time around takes less power to re-manufacture.

I'm not going to do the thesis on it, but I dont think aluminium is as bad as you might think, especially if the power making it is hydroelectric (no carbon dioxide) - like in Tasmania where I was born.

Buddha says Aluminium is God.

[Boston]

all good points my friend
Buddha said that eh
Im going to have to look that up

the embodied energy
depending on what formula is used
generally does take into account the life time energy expended

I would put in a word for wood and say
when I was a kid eons ago living out on the cape
most of the boats in the boat house had been built by some one in the family
and all were wood
so you can see were I get my biased
but if one of em started rotting
and they did every once in a while
boy the phone would start ringing
and some one was going to get a ribbing that they might as well learn to live with for life
white oak seems to be seriously rot resistant
it all seemed to boil down to using the right wood in the right spot
so Im just kinda having fun with you Mr Rwatson as I have no practical experience with aluminum
although I can hear my grand dad yelling at my dad now when he started using epoxy on everything
made old dad pretty grumpy
although one day old pops almost sank ( thank god for wood eh )
and that was the end of the epoxy issue for a while
oh
and my friends and I were just rolling on the shore laughing our asses off while just about everything that could go wrong with a launch did
dad never really got over it
we certainly never let him live it down
was the highlight of the summer if you ask me
I never realized the old man couldnt swim for beens till that fateful day
lmao
Im wallowing in memories now
I think he woulda died if that thing he called a boat was built out of aluminum
ah memories

have a great day my friend
with a fare wind and a followin sea
B

[Jimbo1490]

Both epichlorohydrin and bisphenol-A are endocrine disruptor's.
both are prevalent components in epoxies

This is not accurate. Epoxy resin is synthesized by reacting bisphenol-A with epichlorohydrin. When the reaction is complete there is basically NO epichlorohydrin of any significance left; it has all been compounded into epoxy. Since epichlor is one of the most toxic chemicals around, if there were significant amounts of epichlor still left, epoxy resin would be highly toxic, both acutely and cumulatively, and the fact is it's not. (The curing agents are another story; search the old threads)

Saying that epoxy resin is dangerous because of its toxic chemical precursor, epichlorohydrin, is a bit like saying that table salt is dangerous because it's compounded from that deadly gas chlorine and that highly reactive metal sodium

The so-called 'endocrine disruptor' controversy is highly political, with various environmental political pressure group's propaganda campaigns being the main thing keeping the controversy alive. Using the very same test methodology, scientists have identified very powerful 'endocrine disruptors' much stronger than bisphenol-A in red wine among other things, yet you do not hear the scaremonger groups trying to frighten anyone about red wine, only about various industrial chemicals, because their real motive is to curtail industry in any way they can.

And none of this has anything to do with finding cheap epoxy

Jimbo