|Project by Karson||posted 04-12-2011 03:23 AM||3306 views||1 time favorited||29 comments|
I was Dover Window and Door today, they are a giver of wood for our toy making that the Mason Dixon Woodworkers undertake for underprivileged children for Christmas.
I was talking to the man who glues up the doors and windows and he was showing me the machine that they use to cure the glue joint. It’s a hydraulic press that presses the sides and ends to make sure the item is square. He then cleans up all of the squeeze out glue with a paint brush and water and he then presses a wand over the joint for 10 seconds. It cures the glue in the joint using heat and electric waves.
He then takes it out of the press (after less than 10 minutes and places it on the table and hits the other side of the joint while it’s on the table. Window finished gluing up and glue cured. This is a white PVA glue.
He said that he has also used an electric soldering gun to heat up a joint at home and he also suggested a heat gun to heat the wood to cure.
So I came home to experiment.
I took two craft sticks (Popsicle sticks), put glue on 2” and overlaped the ends. After 30 seconds it came apart easily. I then carried it into the house. wrapped one piece of masking tape over the joint. (There was a slight bow that kept it from having full contact).
I put it in my wife’s microwave for 10 seconds. I took it out, the wood was warm the tape pealed off easily and I tried to rotate one of the pieces of wood and they started to come apart. So I stopped.
I took another two sticks, put on my 2” of glue, wrapped it with one wrap of tape and microwaved it for 20 seconds. Unwrapped the tape and tried to rotate one of the pieces. You can see in the picture that the wood broke. That was after 20 seconds.
I then came back to my computer and picked up the sample that I had microwaved for 10 seconds and it was now fully cured and would not come apart. that was after 10 seconds of microwave and about 3 minutes of cooling down and curing.
So if you need to do some gluing on pieces that you can’t clamp, Use some tape to hold them together and hit them with a microwave.
My microwave might be about 1000 watts. Small cheap microwaves might be 300 watts or so, so do your own testing as to how much it might take to get it cured.
I know I’ll use this sometime in the future.
Revision #1 after 15 minutes of posting.
I picked up the piece that had been microwaqved for 10 seconds and twisted it again. It started to delaminate where it originally seperated. This might have been that the glue was semi cured and when I left them the glue didn’t rebond. It cured and was seperate. I could put my fingernail in the crack and I was able to seperate the two pieces. So they were cured but not fully set up as strong as a bond that was glued and clamped.
I then took the piece that was microwaved for 20 seconds. I got a knife blade at the glue joint and was able to pry them apart with the exception of one small piece where the wood came apart.
So test #3 is now underway. I microwaved for 20 seconds and I’m going to let it cure for an hour or so. The glue squeeze-out is soft after the 20 seconds. Kind of like a 2 -3 hour timeframe. It’s not like an over-night dry time. Even on the sticks that I pried apart the glue was still soft to the fingernail. That might be why it has failed. The semi cured glue is holding it inplace but it’s not fully cured.
These pieces don’t move so I’d have no problem with doing additional assembly if this was a part of a larger project.
I’ll update with the results of further testing.
-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Southern Delaware firstname.lastname@example.org †