I need to make some wide panels for exterior doors, in Sapele. The panels are 58" x20" x 22", double thickness. The door faces north, will be painted, is set back from the porch drip line 8', and the sill is 5' above grade.

I used to use Resocinol to make structural exposed beams, and am used to it. Would it work well on Sapele panels?

I am looking at using Aerodux Resorcinol Resin Kit.

You might end up with the dark line. It should work fine. Probably overkill though. Polyurethane glue is waterproof and more than strong enough to keep panels together.

Personally I would just use Tite Bond II as I have on many exterior doors.

I would suggest using a reactive polyurethane. It will give you higher water resistance than a Type II PVA but will be simpler to use than a resorcinol.

Okay Jeff, what is a reactive polyurethane? I imagine it is the glue that gives you a black hand if you get any on you. Correct?

I know CPA has it, with a less glamorous name.

I used resorcinol in the 70's for exterior work. It came in little cans taped together for catalyst and resin. From Elmer's. It required pressure and heat, but it bonded better than other glues. I still have post caps that look good after 40 years. The wood is nearly gone, but the resorcinol glue line is still there.

I am thinking of going back to it, replacing epoxy in my glue pantheon.

Right you are! It will give you the dreaded black hand. CP carries both the PUR (CP-0701) and the resorcinol (Aerodux 185). The resorcinol will certainly give you the highest degree of water resistance but some people find it a little difficult to use because it's a two part adhesive. If you're already comfortable working with epoxy you won't have any issue with resorcinol.

Here’s a blast from the past 😁

View higher quality, full size image (4032 X 3024)

Thank you for the replies.

Sapele seems to have a lot of oil in it.
When I burn rippings, the oil actually comes out as a flammable liquid.

I think I will give Resourcinol a try.

No one said anything, but the panels are 5/8" thick, not 58" thick.

It has been a while for me, but heat and pressure are what I remember about using Resorcinol.

Heat like over 70 degrees for overnight, with wood, glue, clamps all warm - no chilling along the way. I recall a time whne the boss came in from outside on a cold day while we were gluing up. He left the door open and the temp in the room dropped 20 degrees while it was open. We got him in and unloaded, and closed the door and slammed the heater back on. But that 5-10 minutes that the glue got cold was enough to 'kill' it. Most everything we glued up came apart the next day.

And 5/8" thick? I'll ask the question elsewhere....

Hi David,
With some formulas / brands or Resorcinol the temp was critical. It still is, but with the Aerodux product it's not quite so bad. At 65F he'll get a good cure in 5 hours or so. At 55F it will still cure but take more like 12-16 hours.

Thank you, Jeff. It's good to know about the temperature.

David, the 5/8" thick panels are to match existing in a 90 year old door. The panels are double thickness. The construction is frame and panel, through mortise and tenon, square edged, with panel molding on blocking set in a plough. If the panels do fail, they are replaceable.

When I worked in a shop making laminated beams, the owner would turn the glue room heat up at night to over 100 degrees. The glue would dry hard, but all the wood moved a lot.

Epoxy???????

We have 3 glues on the shelf. Titebond 1, marine type epoxy, and good super glue.

Every once in awhile I used to buy a small bottle of poly for bonding dissimilar materials. It would get used once then end up in the garbage can either because it went bad or because I hate the stuff.

As a side note:

We’ve been using West System G-Flex epoxy for about 10 years for the odd stuff. You guys should get a small kit. It’s the only one that will bond plastics.

Hi all,

So I decided to call CP Adhesives to get some more info on their resorcinol. First, I have to say, they have great customer service. I would not hesitate to call them if I have any questions.
Second, for anyone interested in working with their resorcinol. The open time is 5-7 minutes. Definitely a handy piece of info.

Zach

The 5-7 minutes of open assembly time is correct. However, If you can put the resorcinol down and then stack your pieces immediately to minimize air exposure, you can achieve 12-15 minutes of closed assembly time before you have to have it under pressure.