Replies

1. 
   user-211435 | Oct 09, 2006 06:58am | #1

   I do a lot of fireplace mantles that include crown moldings. 

   The best way to glue them together is to cut the moldings perfectly to fit, use Titebond Type 1 glue, then hold the pieces together for two minutes until the glue tacks.  Set aside to dry completely, then after a while add glue blocks if possible on outside miters, or nails or screws on the inside ones.

   It is important to apply just a small smear of glue with your finger, not too much, not too little, and best on very thick moldings if it is only on the outer edge of the joint to avoid having the moisture in the glue swell the joint apart.  It doesn't take much and it really tacks up quickly, like I said, two minutes usually does it.  The cheapest clamp in your shop is your fingers.  Also the most valuable.  I glue all small moldings this way.

   Hal

   http://www.rivercitywoodworks.com

2. 
   TaunTonMacoute | Oct 09, 2006 11:08pm | #2

   I'd do it pretty much like Hal advised except I'd use Titebond Wood Molding glue.  It's thicker, tackier, and sets a little more quickly.

1. 
   Argonaut | Oct 11, 2006 02:31am | #3

   Thanks to all. I ended up trying three glues: ProBond (like TiteBond II), Weldwood, and a cyanoacrylate jel from "2P-10" (recommended by my wood dealer). All ended up with a firn joint overnight using the 'fingers-for-clamping' method, but my preference is for the Weldwood. It left the strongest joint (ripped away some MDF when destroyed, and all the others snapped cleanly and more easily) and was the simplest to apply.The 2P-10 soaked into the MDF (yes, this is MDF molding, sold by the same guy who recommended the glue) and provided no gluing effect at all until I applied it for the third time. Then of course the surface was dried glue, and it worked fine (it sets in 10-20 seconds even without its accelerator spray). However, at $8 per ounce, that's not going to be in my repertoire for long.Learning a lesson, I applied a glue-size of ProBond and water to a fresh joint, waited for it to dry, and then used the ProBond. Worked fine, as you guys advised.With Weldwood, there is no need for the sizing. Just apply thinly and wait for it to get tacky, about 10 minutes. Then press together and in a minute or so you can release it. That's faster than the ProBond. The instructions say if you must clamp, clamp lightly, so the finger-clamp method is perfect. It also dries clear, unlike the yellow glues.So, the 11-pice cornice is drying, and I'm hoping it will fit (g).

1. 
   justinh | Oct 11, 2006 06:57am | #4

   2P 10 makes a Jel glue that works well on MDF mouldings.  It's thicker and doesn't soak in.  The accelerator however does so I spray it directly on the glue rather than on the opposite piece.  It also makes the glue pop in about 5 seconds.  It also works well as a clamp in combination with yellow glue holding pieces together until the wood glue dries.

   Collins tool company makes miter pinch clamps which I find very useful when pre assembling miters.  Combined with a micro pinner they make the job much easier.  They leave small indentations which often require little or no filling before finish.  If you decide to try them purchase the clamp wrench with them.  It makes them much easier to set and if one happens to slip and clamp one of your fingers it makes them much easier to get off.  Don't ask how I know that :)

   When pre assembling crown I also like to straddle the backs of the miters with fine wire staples after stitching the front with pins. It makes for a strong joint that can be moved if careful while the glue is still wet.

2. 
   user-211435 | Oct 11, 2006 07:36am | #5

   I think you may find that all yellow carpenters glues are not created equally.

   For instance, Titebond works differently than Elmers.  You are doing the right thing in finding what works best for you. 

   Even the three (or maybe more) Titebond glues, which include Titebond I, Titebond II, Titebond III, etc, are all so much different from each other that you would not know they are the same brand except for the label.

   I use Titebond Type I for most of my work.  I use Titebond Type II waterproof for some things that need to be waterproof or if I need a longer open time.  This glue is also less heat sensitive so it creeps less than Titebond I which makes it great for curved laminations.  These are both really great glues.  I use West System epoxy for many things.  I use Titebond's new Type III (I think it is called that) Ultimate Wood Glue sometimes, although I don't think it is the ultimate wood glue... 

   My point is that it depends on the application.  You should try Titebond Type I though if you haven't already.  It works really well for most applications and if you buy it by the gallon it is reasonably priced.

   Hal

   http://www.rivercitywoodworks.com