The demise of Araldite 1253 and emergence of a better epoxy.
If you are not an experienced conservator, please consult one before using any of this information. Epoxies, once cured, are very difficult, if not impossible, to remove or reverse. There is a thought process conservators go through when considering the use of epoxies. Most of us use them sparingly. Please proceed with caution.
If you are a conservator: Keep in mind that about half of what I conserve are “objects in use” owned by private individuals: chairs, tables, chests, beds, etc. that will see careful, but daily use. My need for a more structural product is probably different from someone who conserves objects solely for display in a museum.
Although I mention a lot of brand names, I am not paid by any of these companies nor have I ever received free samples of these products.
The Backstory:
In 2016, the conservation community was upset after Huntsman discontinued making Araldite 1253 epoxy paste. Most of my colleagues agree that the most challenging part of our job is sourcing materials and dealing with the “how am I supposed to manage” moments when our favorite materials and tools disappear from the marketplace. Araldite 1253 was a staple of wooden artifact conservators, but was always difficult to source. Huntsman was the last manufacturer of this epoxy, with Vantico and Ciby-Geigy preceding them. There were no direct sales so we all had find distributors for this product. Most were not ‘conservator friendly’ in that they preferred selling “super tanker” size quantities. I had few experiences where the distributor seemed even the least bit motivated to sell the product. In the early 1990’s, one distributor refused to sell it to me because they did not think I was qualified to use it. A few years before 1253 was discontinued, I was purchasing it from Freeman Supply and they were a very reliable and friendly source. They still have a PDF of a data sheet for the product if any of you are interested:
https://www.freemansupply.com/datasheets/Araldite/1253.pdf
What I most appreciated about 1253 was the ease of mixing it and its carvability once cured. It was basically a 1:1 mixing ratio so it was simple to use. Once cured, it carved like soft wood, maybe better because there was no grain to contend with. In addition to the difficulty most of us had in purchasing 1253, it also had a relatively short shelf life. The resin and hardener would thicken and get crumbly making mixing difficult. On more than one occasion, I received expired 1253 from a distributor I will not name. Now looking back at all these negatives issues, I wonder why I did not start looking for alternatives much sooner. I suppose I did not have the experience to know what I needed. This is the nature of wooden artifact conservation. Formal instruction is scarce and even if it was not, the variety of materials, designs and construction techniques that cover many centuries is something I began to be confident with only after 30 years. (I’m more comfortable with doctors and airline pilots with similar years of experience).
Some alternatives I worked with that helped me find a better thick/paste epoxy alternative to Araldite 1253:
During this time (late 1990’s), I found a product called Sig Epoxolite that I’m still convinced was simply re-packaged Araldite 1253. I could see no differences between Epoxolite and Araldite 1253. Even the colors of resin and hardener were identical. I purchased Epoxolite during the times when it was impossible to obtain Araldite. (Sig is a company that as of May 2024 still specializes in model airplane making, but sadly no longer not lists Epoxolite online.)
By the early 2000’s conservator Len Hambleton told me about PC Woody epoxy. It is still being made (as of 5/15/24) and is similar (but not identical) to Araldite 1253. The resin and hardener are slightly different colored from Araldite 1253 and the final cure of the material is noticeably more brittle/friable, but still carvable. I did not like the brittleness, so I decided not to use it and thus I have very little experience with it. This does not mean you should avoid it too. It is available in small quantities on the retail market. https://www.pcepoxy.com/products/wood-repair/pc-woody/
Renpaste 427 is also similar to 1253. It is part of the Araldite (spelled Araldit in Europe) family of epoxies made actually by Huntsman, but only available outside the United States. In Europe, the Araldit name is also associated with DIY or retail type epoxies, similar to the thinner clear epoxies sold here in the US under the Devcon name. I’m sure there is a history of the name Araldite/Araldit. I just haven’t gone down that far down the rabbit hole . . . yet.
I credit conservator Nancie Ravenal (I think it was the late 90’s) with getting me to consider West Systems epoxy instead of Araldite 1253. Maybe she too had run into the same roadblocks sourcing Araldite 1253 that many of us faced. I had used West System in the 1980’s and knew boat builders who considered it a staple, but did not have enough experience to realize that all epoxies are more closely related than manufacturers would want us to know. The short version of this tale is that by bulking West System epoxy with their fillers, I was able to eventually get the viscosity and carvability I appreciated in 1253.
Still, it took a while to wean myself from Araldite. This was in the 1990’s and while I had a few years under my belt as a professional woodworker, I was new to conservation. So I accepted without question that 1253 was a ‘conservation grade’ material and that there was something ‘special’ about it. It took a few more years to understand that materials chosen by seasoned conservators are chosen because of the deep research and experimenting done on a given product, (paint, glue, soap, etc) to understand the material’s characteristics (composition, reactivity, lifespan etc.) This research does not necessarily have to be done in a university laboratory but by anyone with a critical scientific mindset in almost any environment. It’s always helpful when the manufacturer potential conservation materials is forthcoming with ingredients and formula.
The qualities I was looking for:
This has been a perfect example of why conservators we should always be questioning the material and techniques we use and be constantly looking for better ones as well as similar alternatives. It is often that a material or tool that we rely upon will suddenly become unobtainable. Years ago I cursed Huntsman for taking 1253 away from us, but now feel like thanking them for forcing me to adapt. I ended up finding materials that outperform Araldite 1253. The combination that I’ve been using for about the last 10 years has been West System’s G-Flex 650 mixed with West System 407 filler (phenolic microballoons, I think?). When the filler is added to the mixed epoxy to what West System calls ‘peanut butter consistency’, one can approximate the performance of Araldite 1253. Once cured, it feels a bit smoother or less friable than Araldite 1253 when using a carving gouge or chisel to shape it. In testing, I’ve found it to be less brittle than Araldite 1253. That is: it would NOT fracture as easily when driving nail or screw into it. This increased flexibility or modulus of elasticity might very well be more desirable for certain applications. It is not flexible in the sense of silicone caulk, but simply not as brittle as some traditional epoxies.
I think the G-Flex/407 filler mixture is better than Araldite 1253 for the following reasons:
It is easily obtained through many internet sources
It is available in small quantities
The shelf life is better than Araldite 1253 (see note below)
Its performance and handling are easily manipulated with West System’s variety of fillers.
The viscosity is completely controllable by simply reducing or increasing the amount of filler.
Based on 30 plus years of daily experience with epoxies, I believe this West System blend is more elastic, flexible and shock resistant than Araldite 1253.
West System’s product support is better and easier to access online than Araldite 1253 ever was.
West System has published an incredible array of instructional literature.
G-Flex 650 is a regular viscosity product and G-Flex 655 is a higher viscosity product. Both are useful and seem to perform similarly. One might prefer the thicker/more viscous 655 if you need to start out with a thicker mixture to begin with. To further complicate this scenario with options, there is another West System product called ‘Six10’. I have no experience with this product, but I intend to ask West System what the differences are (when I have some free time . . . not likely any time soon). I hope someone beats me to this.
The one disadvantage of this G-flex mixture (when compared with Araldite 1253) is that it requires significantly more time to mix: You first have to mix the two-part G-Flex 650 epoxy and the add the 407 filler to the desired viscosity. (Araldite 1253 was basically a 1:1 mix straight out of the containers.)
I add the 407 filler little by little to the desired consistency. I’ve never taken the time to measure exact amounts of filler that I use. I think that West System purposefully removed potential for numerical mixing errors out of the equation by simply instructing us to mix according to familiar consistencies (ketchup, mayonaisse, peanut butter, etc). What I like better about this is that I can tailor the viscosity/consistency to the task. Be aware that getting to thick viscosity of Araldite 1253 (peanut butter) takes a more filler than you might think. I’m using at least twice as much filler by volume as epoxy resin and hardener, probably more. Make sure you test some mixtures before committing them to a real project. A little practice and experimentation will pay big dividends.
Many of you might be familiar with West System’s 105 resin and various hardeners. Here is a guide to how to choose between the 105 family and the G-Flex family:
https://www.epoxyworks.com/index.php/which-epoxy-is-recommended/
For years, I used the 105 family because G-flex had not yet been developed. It’s a great epoxy system and the difference between this and G-flex is fairly small and not greatly noticeable when used for most conservation. The fillers that West System makes can be used with either and the fillers can truly help you customize the results you get. Many thanks to conservator John Coffey for suggesting I try the G-Flex family of epoxies.
For an easier-to-carve material than the G-flex/407 combination, I’ve used G-flex or the 105 system with the 410 filler. Although not as structural, this is a perfect blend for compensating missing areas that are purely decorative and not subject to stress. Another option for this application Abatron’s Wood-Epox. It is perhaps even easier to carve than G-flex and 410. (more on Abatron below)
I’ve used West System epoxies (including G-flex) with fiberglass and carbon fiber cloth and it performs wonderfully.
Other Epoxies I recommend:
Abatron Wood-Epox is a two-part 1:1 ratio epoxy that is VERY thick yet VERY lightweight. It’s not like Araldite 1253 or the G-Flex mixture at all, but I find it very useful for other scenarios. I don’t generally use it for bonding, but rather for replacement of large losses that need lots of shaping and carving. I’ve used it for compensating losses to deeply carved gold leafed frames. This material accepts gesso well. It carves easier than anything listed above and anything I’ve ever used. It is very easy to mix. It can be shaped while in the uncured or semi-cured state. It is easily sourced and formulated specifically for wood restoration. Abatron also makes a VERY thin epoxy called Liquid-Wood and can be used in conjuction with Wood-Epox for the consolidation of rotted or insect damaged wood. Abatron is a proven product with a loyal following and excellent product support:
I’ve used some System Three brand epoxies over the years. I used T-88 from the 1980’s through 2010 and was always happy with it. I think the modulus of elasticity of T-88 is slightly less than G-Flex 650, but maybe not enough to notice for our purposes. If you are presently using System Three epoxies, I don’t think there is any reason to switch. System Three probably has fillers that will give you the same results that I get with West System.
Aero-Poxy Light is product that looks like it might be similar to 1253, but I have yet to work with it. I have been wanting to it AeroPoxy Light since Sue Ann Chui posted it on the AIC/ConsDistList forum some years ago, but because I have been using the West System family of epoxies and fillers for so long always have a supply on hand, I haven’t gotten around to it. The website below is the manufacturer I believe, but there does not seem to be a way to order it online.
https://www.ptm-w.com/aeropoxy/AEROPOXY%20Product%20Bulletins/AEROPOXY%20Light%20Bulletin.pdf
Final Thoughts:
More eco-friendly or ‘green’ epoxies are now on the market and more being developed. At some point, I will begin experimenting with them.
How long do cured epoxies last? How ‘archival’ are they? I do not know. I am unaware of any research/scholarship concerning the aging of epoxy. I’m sure it depends on the movement (expansion and contraction) of the material it is applied to. In our case, wood. Here is an excerpt from the book Details of Classic Boat Construction by boatbuilder Larry Pardy that discusses issues with epoxy as it relates to boatbuilding: https://cdn.shopify.com/s/files/1/0502/6086/9275/files/ClassicBoatAppendix.pdf?v=1614109773
The use of composites (epoxies being one of the main constituents) is something worthy of study by not only conservators but anyone who designs, makes or repairs things. I recently watched this Make Magazine interview with Ned Patton, the author of The String and Glue of Our World. I recommend watching/listening as well as reading the book.
