Posted this also under "The Story of My Liquid Nails Fail." But is relevant here as well.
REVISION: LIQUID NAILS SUCCESS NEW TEST: Liquid Nails vs. Epoxy -1- Liquid Nails, spread thinly with putty knife, on smooth flat beveled-cut surface, with some tiny holes scratched into both facing surfaces with a wallpaper scouring tool, then clamped and cured for 24 hours, works BEAUTIFULLY! Incredible strength. And Liquid Nails *claims* its repairs will outlast the life of the original material. Am going to trust that it will last for my purposes. -2- Epoxy, surfaces prepared the same way as above and spread evenly over entire face, simply did not dig in to anything but the utter topmost layer of polyiso fuzz. And the adhered parts easily snapped apart after 24 hours cure time. When snapped apart, I observed the epoxy "bond" covered with maybe 1/100 inch of polyiso fuzz. Is possible that if I had punched a lot of tiny 1/2" deep holes in each face and smeared on the epoxy much thicker to fill those punched holes, that I would have gotten a stronger bond. But, given the positive results with the Liquid Nails, once spread with a putty knife, and its *substantially* lower cost, I am not going to do any further testing with epoxy resin at this time. Also is possible that epoxy would work with NEW polyiso boards. Mine are salvaged boards, possibly 20 or more years old. (They do age, outgas, lose R-Factor over time. And maybe mine are fuzzier along my cuts than new boards would be. I don't know.) So ... I am going with the much less expensive Liquid Nails for my project. That means I must create some 30-degree-angle braces (out of 2x4s?) that I can clamp onto roof-cone sections as I glue them to hold the adhered parts together tightly for the 24 hours cure time. And created 30-degree-angle braces for the wall sections. As an additional measure, am going to use an awl to punch a dozen or more 1/4" deep random holes along each face to be adhered to allow for much greater material penetration in those spot, expecting that will make for a stronger, more durable bond once cured. Also, am going to test using rubbing alcohol or acetone on a cloth to lightly rub the surfaces to be joined to see if that will help clean away dusty fuzz. (Or whether it melts the polyiso.) Additional observations regarding my earlier Liquid Nails fail: Because I was attempting to reattach two broken pieces with very uneven faces, I was not able to smoothly smear Liquid Nails on the broken faces. But on smooth-cut bevels, it smears easily, evenly, with a putty knife despite its vicosity. In this latest test, I applied it to only one of the two surfaces to be joined. I don't recall for sure, but think I might have applied it to both surfaces of the broken pieces in the test that failed. On Wednesday, August 16, 2017 at 2:54:31 PM UTC-6, ken winston caine wrote: > > Fail was my fault. > > 1. I didn't clamp the boards after gluing. > 2. I thought a 70 lb. pallet would be adequate to keep a wind gust from > causing a problem during overnight cure. > 3. I had assumed the Liquid Nails compound would be less viscous and more > grabby and that I could spread/smear it over the entire surface of each > face to join. Not possible. Instructions say to apply in a zig-zag design, > so that is what I tried. <snip> > > > -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To unsubscribe from this group and stop receiving emails from it, send an email to hexayurt+unsubscr...@googlegroups.com. To post to this group, send email to hexayurt@googlegroups.com. Visit this group at https://groups.google.com/group/hexayurt. For more options, visit https://groups.google.com/d/optout.
