Friendly Fiberglassing: Can Hide Glue Replace Epoxy?

Hide glue has been around for thousands of years, and some of it is holding wood pieces three thousand years after application. It is made from animal protein, so vegetarians may want to stick to the petroleum-based adhesives. [Surjan Singh] wanted to see if its longevity made it a contender with modern epoxy by casting a couple of fiberglass car parts with the competing glues. In short, it doesn’t hold up in this situation, but it is not without merit.

Musical instrument makers and antique restorers still buy and use hide glue, but you would never expose it to heat or moisture. To its credit, hide glue doesn’t require a ventilator. All you need is boiling water and a popsicle stick, and you are in business. [Surjan] writes his findings like a narrative rather than steps, so his adventures are a delight to read. He found that a car part made with fiberglass and epoxy will withstand the weather better than the alternative because heat and humidity will soften hide glue. His Saab 96 isn’t the right application, but since it is nearly as strong as epoxy once set, you could make other fabric shapes, like a flannel nightstand or a lace coffee table, and you could shape them in the living room without toxifying yourself

No matter how you want to work with glues and substrates, Bil Herd has you covered, and here is an excellent tip for a cheap degassing setup.

40 thoughts on “Friendly Fiberglassing: Can Hide Glue Replace Epoxy?

        1. The two main categories are health reasons and moral reasons.

          Calling morality “activism” denies that there is any difference in moral views, and is very dismissive.

          Activism would be less than 0.1%, and would be almost entirely public figures.

    1. Some people who don’t eat meat can smell products made from dead animals, and people who eat dead animals. Not sure what it is but it could be traces of molecules such as cadaverine and putrescine. There are stories of the viet cong having the same ability to smell American soldiers for the same reason.

      1. Model airplane folks often use CA glue with fiberglass for small patches, because it’s lightweight and the strength comes from the glass anyway. For bigger areas, folks use water-based varnishes: many swear by Minwax Water-soluable ‘Polyurethane’.

        Titebond II (diluted) and strong paper is another classic fiberglass substitute for wing covering.

        I’ve never heard of Titebond + glass, though, but it’s surely worth a try if you have both in the basement anyway.

        Me? I just use fiberglass and epoxy. I’m not allergic to the stuff, and it’s soooo much nicer than polyester resin that I hardly hesitate.

        1. I’ve heard too many accounts, and experienced some myself, on CA glue failing under vibration. Fractures, usually letting go without warning.
          I haven’t heard of nor tried yet with the ‘rubber-strengthened’ versions of CA.

          And there are so many epoxies to choose from too.

      2. Very much so.
        With the right ‘resin’, could be that end-of-life means softening the ‘resin’ and reforming the fibreglass, then hardening again. Like heat & moisture with hideglue.

        There are additives for hideglue that make it:
        – more resistant to water
        – fully resistant to water

        Also wondering about shellac…

        Perhaps a waterproof topcoat, that could be removed at end-of-life, exposing the glass with resin for reforming.

        I’ve used flour and also corn starch for extenders when using epoxy resin as a filler. Try with hide glue?

    1. Titebond is amazing! I use it to finish 3D prints, as a paintable smoothing agent, with a little heat to make it stick better, and you can use it instead of water with Durhams putty.

      I’d try it with fiberglass, but I also don’t want to mess with or touch any fiberglass at all if I don’t have to, much as I love the finished result more than just about any material. I wonder what other strong composite reinforcement is available that’s not so awful to work with? Are there any that cost less than kevlar besides paper mache?

    1. Big layups of fiberglass for boats and cars are not done with epoxy but with polyester resin which is adequately strong and far cheaper. Epoxy requires a top coating if used outdoors as it is quite sensitive to UV damage. In the former East Germany they had a smoke belching disaster of a car called the Trabant. Instead of fiberglass, the reenforcing material was waste cotton cloth.

    2. Ive always wanted to epoxy impregnate Wood-filament PLA prints-

      thin walled wood-PLA painted with resin and coated in tissue for super light plane parts, but the heat by-product of the curing process always made me unwilling to try

  1. Great Idea!

    As a former professional auto fabricator who worked with composites, I’m worried about the sustainability of making things that last longer than their usefulness.

    This is very inspirational. Thank you.

  2. Boiling water? It should be 140-150F. Don’t mix in a glass dish and let it dry out. It will stick to the dish and rip shards out of it without breaking it in two. One of the few adhesives that stick to glass.

  3. About 20 years ago I got interested in building wooden instruments. Think guitars and fiddles.
    And I lernt about glues to use. Especially hide glue.

    And lernt that hide glue is gelatin which is what Jello(TM) is made of. And that folks in a pinch to make a repair might go to the grocery and buy unsweetened gelatin — a bit expensive but works just fine.

    Don’t use Jello(TM) — the sugars and such will make it susceptible to mold and rot.

    But after these studies and lerning I came to realize that violins are made of wood and JELLO!

    A wee bit of hilarity to share with you ………

    Jim

  4. One of the tradeoffs of hide glue that makes it so useful in instruments is that you can take a finished instrument to pieces easily and with minimal damage by careful application of heat. Most fancy wood instruments have high stress parts fail after a while. It’s nice to be able to dis- and re-assemble it like it’s a LEGO instrument.
    Same thing holds for some old furniture. Things that are likely to break, like the runners on rocking chairs, are way easier to replace if attached with hide glue.

  5. Actually, I’m more interested in finding a substitute for the fiberglass. Of all the nasty materials to work with, I put it right up there with CA Accelerator and hydrofluoric acid (joke). I have an old linen shirt I’m going to experiment with. I’ll try the hide glue with it – All Natural?

  6. Hide glue was also used in traditional Mongolian recurve bows. Most of the tension of the bow arms was kept in strips of horn glued to the back side of the bow arms and they were much lighter and shorter which made them easier to fire effectively from horseback. As I understand that there are some historic accounts about how the easiest way to fight Mongolian horseback Riders was to wait for it to rain so that their bows would be less effective or more prone to breaking.

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