Saturday, December 03, 2005

I Don’t Know What The Hell Is Going On

I tried to put the first extension on to a door tonight and it didn’t go well at all. I guess I shouldn’t say that. It did go well up until the very final step. Now the wood is stuck on, but not well, and I can’t get it off.

The extension is about 6-inches wide. It is designed to go at the top of the door and add 6-inches to the height. I cut and planed these two pieces for two doors and they came out very nice. I paid special attention to wood selection and everything looked good.

Because I don’t have clamps that are 8 feet long the plan was to use lag bolts to bolt the new pieces to the doors. This should hold everything secure while the glue sets. The bolts would also add extra strength. I used four 6-inch lag bolts per door and counter sunk them 3-inches. There would be 3-inches of bolt in each side of the joint.

I clamped the boards together from the sides to make sure everything matched up well. I then pre-drilled all the holes. I took it all apart and glued up the joint. It all seemed to be a very good fit. The problem arose when I got to that last little bit….

Ok, I just got it off. While writing this I realized what the problem was. I had to cut two of the bolts off with the sawzall to get it off, but it had to be done over. The gap was small but it was just big enough to get a sawzall blade in. The problem arose because the bolt is threaded on both sides of the joint. It will never get any tighter than it was when the first thread was cut on the opposite side. I don’t know if that makes since.

In order to draw two things together tight with a bolt only one side can be threaded and the other needs to be able to move freely. Since both sides were threaded if you didn’t have a perfectly tight joint to begin with you would always stay the same distance from the other piece. The trick is to have the threads only on the door side and not on the extension side. Another way to do this would have been to clamp everything tight and then drive the lag bolts in. As I already said, I don’t have 8 foot long clamps. (I need pipe clamps)

I think I’ll be able to salvage the addition I cut. What I will need to do is drill out the hole for the bolt so the bolt moves freely in the hole on the addition piece. Then as I thread it into the door side it will be drawn closer. The reason I couldn’t get the old bolts out was because I tried to tighten them too much to close that last 1/16-inch gap and I stripped the threads. You would think that with stripped threads the bolt would just come out, but no. It merely turns in the hole and there is enough there to keep it from coming loose. I could have gotten a pry bar and tried to separate the two and force the bolt out but I would have most likely damaged the door.

Luckily I got it off before the glue set, otherwise I would have been totally screwed. In a way this blog really paid off this time. By sitting down minutes after it happened and writing about it, I went through everything again in my mind and discovered the problem. Thank you Petch House Blog.

What a drag this whole thing has been. Chalk this up to inexperience, I guess. Norm wouldn’t have made this mistake.


derek said...

In woodworking class, we learned that the screw move freely through the piece being attached (no big enough so that it goes through though). Or you always end up with a gap.

Anonymous said...

i don't think norm would have admitted his mistake! you've got a horseshoe stuck somewhere on your person, otherwise when you figured it out, the glue would have been set!

and... you need to publish or reject the comments being placed by your loyal fans since you turned on the "moderation", otherwise how are we to see the comments?

slateberry said...

I too have to lengthen a door, and I also don't have long clamps. I've been planning to improvise by adding blocks above and below the ends of the door (beyond the strips I am gluing on) to protect the door from rope compression marks, then wrapping loops of tight rope every few inches, then tightening each loop by inserting a strong stick, twisting, and securing. It _sounds_ hokey but who knows--perhaps it's a time-honored technique. I'll let you know how it goes. You've scared me away from the lag bolts anyway.