Replies

1. 
   Fred_Matthews | May 26, 2000 06:06am | #1

   *
   joel:

   I use urea formaldahyde w/ good results....I'm not exactly sure how resorcinol differs in its properties, but would be curious to get any feedback.

1. 
   Howard_Acheson | May 26, 2000 09:07pm | #2

   *Resorcinol glue is a two part product and is one of a few adhesives that meet the Type I waterproof test. Type I requires that it maintain integrity when it completely submerged for long periods and at high temperature. Most two part epoxy adhesives also meet the Type I spec.Adhesives such as Titebond II and most polyurethenes meet the Type II spec which means the adhesive should be used underwater or in a high temperature liquid.Personally, I would use a PVA Type II such as Titebond II or a Poly. Both would be fine in your application. A negative with the recorsinal is that it leaves a purple glue line.

1. 
   gpwestmoreland | May 27, 2000 04:51am | #3

   *Howard, By any chance, should there be a "not" in your 3rd paragraph, as in, "should NOT be used underwater"? Thanks. GP

1. 
   Howard_Acheson | May 27, 2000 09:36pm | #4

   *Opps, you're correct. Thanks GP. Consider it corrected.

1. 
   Joel_Watson | May 29, 2000 01:37pm | #5

   *I've heard that the PVA glues creep under stress, allowing joints to work loose. I haven't experienced this with light casework I've made, but was concerned about it for the door. What's been your experience on that?

2. 
   Howard_Acheson | May 29, 2000 05:49pm | #6

   *Joel, Yes, PVA glue has some propensity to creep under shear type applications. I do not think there would be any significant shear stress in a properly designed door. I have never had a shear stress failure with PVA Type II adhesive but I would never use it in a bent lamination for example.

3. 
   William_Tandy_Young | Jun 26, 2000 03:54pm | #7

   *Joel:If you're building a frame and panel exterior door, a Type II PVA should hold the mortise and tenon joints well enough (pin them too, if you can). Although the PVA will creep, it shouldn't be much of an issue in that case. If the door will get blasted by sunlight, choose another glue. PVA joints degrade with exposure to intense light (edge joints more so than mortise and tenons). If you're pressing the door as a large laminated panel, don't use PVA--it's not rigid enough.Urea resin glue (aka plastic resin glue) is more rigid and moisture resistant than Type II PVA, but it's not completely waterproof. Since it tends to break down more readily when subjected to heat, it shouldn't be used if the door will receive a lot of thermal gain from sunlight. Resorcinol is a good choice. It's rigid and waterproof and holds up well when subjected to heat. Many paint and hardware stores sell small quantities of consumer grade resorcinol. This material isn't quite as good as industrial grade stuff as a rule, but it's still fine and it will work. You can't control the viscosity of it because you're mixing a pre-formulated liquid resin with a powdered catalyst, and it may be thicker than you'd like as you apply it. Don't apply more glue than needed, so you can keep the dark purple squeeze-out to a minimum.Polyurethane glue has superb heat resistance, but is not completely waterproof as advertised. If the door isn't going to get routinely weather-soaked, it will work fine. It's premixed, and ready to use. Don't use it if your joints aren't tight and well-fitted, though. It turns to foam where gaps in joints occur, and loses much of its structural strength.