Sunday, October 26, 2008

Some Assembly Is Required, Part 2

I had started writing part 1 of this 2 part report a few weeks ago. And then October got busy with things besides the pulpit. We had a revivalist, Dr. Gabriel Heymans and his wife Anita, visit our church. They ended up staying for two weeks, and I spent almost every night at church. I spent every night of the next week working on the center box, trying to make ground on it. I finally got a chance to finish part 1 over the weekend, and now I'm bringing it up to date.

In part 1, I recounted putting the two side boxes together and the issues I found with mis-cut panels for the center box. Now it's time to address the issue.

As I said in part 1, I decided to remake the rails for the center box in order to recover from my mistake. But first, I had to cut off the bottom rail I had glued into one side.

I didn't want to risk damaging the post, so I pulled out my Shark flush cut saw (the only hand saw that I have that I really trust myself with for this kind of work) and cut the rail off about 1/8" - 1/4" from the post. Next, I used a chisel to pop off the shoulders of the tenon that were left on the post. Since the joint there is end grain to long grain, they popped right off.

I set up my plunge router with the same 3/8" straight bit I used to cut the groove & mortise. I set it up for a maximum plunge of 1/2", as I did when I first cut the grooves. Next, I attached my edge guide & set it close to where I needed it. To fine tune the position, I placed the router in position & turned on the router. I lowered the bit down so it just kissed the surface. I then carefully adjusted the edge guide so the bit was cutting the wood I needed to remove and only that wood.

When I was satisfied, I made the two passes, the first at 1/4" and the second at 1/2", to re-establish the full length of the groove. This went perfectly well.

I then reset the maximum plunge of the router to 1 1/16". Everything else was left unchanged. I then remove the tenon material left in the mortise. This went well too. In fact, I found some stretchy glue residue left over in the mortise that I was able to remove with a chisel. I just had a little clean up to do with a 3/8" chisel & I was done.

I went out to Condon's & picked up a board that I intended to use to remake the rails. I wanted to get a 5/4 D2S board, but some how I miss measured at the yard & got a 13/16" D2S board instead. I did have some boards left from the original order that I was going to use to make the lectern, but I decided I could use them for the rails instead & use the D2S board for the lectern.

Incidentally, everything described from here on happened in the evenings after work the week of October 18.

So I milled those boards. Somehow, my Wixey digital planer height read out got about 1/16" off. And, of course, it was reading 1/16" higher than it really was. So the boards I milled ended up being 13/16" thick instead of 7/8". The trouble is starting already! I decided to mill the 3/8" groove off center & keep the narrow part on the inside.

I ripped the parts to width & cut them to length. I milled the groove by mounting my 3/8" straight cutter in my table mounted router & setting up the fence & some feather boards. This went OK and the grooves were done. Then I carefully cut the tenons. And I did the first dry fit -- a real dry fit. I didn't glue anything together before the dry fit.

The middle rails were fine, but the top & bottom rails were still too short! I forgot to account for the extra 1" of tenon on these parts when I calculated how long to cut the parts. Doh!! At that point, I knocked off for that day.

I went back to Condon's, and this time, I got a 10' long board that was a true 5/4 thick and about 4" wide. Actually, it's width tapered from about 3 1/2" or so to about 4 1/2". I had them cut it in half so I could get it in my Accord to take home. If I didn't screw up anything more, I would be able to get all the wood I needed from half the board, so this was to my advantage, anyway.

I cut the new board into pieces of rough length. I face & edge jointed, then watched the thickness carefully in between passes. I used one of the original rails to gauge the thickness as I milled & I stopped when they were about the same. I used my fingers to make that determination, not a ruler. The new parts are as close to being the same thickness as I can feel.

When I was happy, I ripped everything to the proper widths, but I still didn't cross cut anything. Next, I set up my aux fence on the table saw & mounted my dado set, at 3/8", to the saw. I set the fence 1/4" from the blade & mounted a feather board on the fence to push the stock down to the table. And I ran the parts. They came out great.

Next, I cut the parts to length. I took the length of the original top rail & added 1 1/4" to it. That's the length I cut the top & bottom rail stock to. Then I made the tenons on the end. They came out well, too.

Dry fit time. This time, everything came out the right length! Big sigh of relief!

Next, I made new front stretcher / shelf supports from ply. I ironed on some edge banding to hide the ply edge grain on the inside. And it's time to make new shelves. I cut the 4' x 4' half sheet of ply I had left over from remaking the other shelves into four blanks. No problems here.

I used some left over pieces from the failed second set of rails to make the edging for the new shelves. I planed them down to 3/4" thick and then ripped them to the right widths & cross cut them long. The space between the posts would be 20 1/4", so I needed them to be at least 21" long, if not 22".

I glued the edging on. I left them in the living room over night to dry on Friday night. It's gotten cold here in Westchester, and I don't think I can leave stuff in the unheated garage to dry and get a good bond. I've had enough go wrong so far that I don't need the edging to fall off if someone leans on a shelf.

On Saturday, I cut the notches in the new shelves. This time, I made a few changes to my technique. First, I put my stock fence with the tall aux fence still attached to it & put it in the right miter slot & made a pass. This established a width for ripping that piece of ply so I wouldn't have to remove the fence from the miter slot if I needed to swap miter slots. I then ripped the fence to that width & put it back on the miter gauge.

Second, instead of nibbling away the material, I set the blade height for one side and made one pass to establish one shoulder at that particular blade height for every cut that required it. Then I set the blade height for another side & made all of those cuts. I repeated this until I had all of the notches made. This time, they went a lot faster & came out real nice.

I finished up drilling the pocket holes I needed to attach the top rails to the boxes later. I had to drill these before assembling the box because I wouldn't be able to fit the drill & bit inside after assembly -- the top shelf isn't deep enough for the bit & drill to fit. Holes were drilled on the inside of the front rail, along the outside of the ply partitions where they will touch and will never be seen when the three boxes are assembled to each other.

Time for one more dry fit. Everything looked good. And I glued it up. And I finally got all three boxes assembled!

Here's a picture of the center box with the clamps still attached after I glued it up.

And here's the top shelf. The wood is still wet in the corners where I wiped off some glue squeeze out with a wet rag.

And finally, here are the three boxes, bolted to each other for the first time after the glue dried.

We're just about up to date. I did a little bit of work this week after work, but I'll leave that for next time.

Tuesday, October 7, 2008

Some Assembly Is Required

The raised panels are shaped & finished. The frame parts are all made. It's time to do some box assembly! The crowd goes wild!

Well, almost. There's a few odds & ends in the way. You see, I found out during one of my dry assemblies that some of the shelf pin holes I drilled weren't deep enough. My fault for not testing my set up on my plunge router. I even missed a couple of holes on one post. Considering there were 12 posts that needed shelf pin holes, that's not bad. And I hadn't drilled all of the pocket holes I need, either. And there were a few parts that needed more sanding. And I found a couple of gashes had magically appeared on a couple of parts. And I still had to cut the notches on the 10 shelves I had remade a couple of weeks earlier.

In fact, I made a list of 31 steps I needed to perform in order to complete the assembly. These included things like cut the notches in all shelves, sand the shelves, disassemble a box, re-drill the shelf pin holes, etc. Hey, I'm detail oriented & anal, what can I say?

So I took a Friday in September off from work & got to item #1 on my list: Cut the notches in the shelves. And that took all day to do. So much for the best laid plans of mice & men, eh? I am happy to say that they came out much better than the last bunch of shelves I had cut.

To do these, I set my combo square to the depth of the front posts on one of the boxes and I used that to set the height of the blade on my table saw. I also used it to lay out the depth of the notches on the front corners. Then I set my combo square to the length of the notch, and I used it to lay out the length of both front notches on both top shelf blanks.

Next, I took my stock miter gauge, which still had the auxiliary fence I had installed the last time I cut notches attached to it, and I made one cut. Just one. And I took the shelf over to the wing I had used to measure everything. And the cut was too far from the corner -- it looked like I'd screwed it up again.

Blood pressure rises. A primal scream escapes the lips. Luckily, the kids were at school & the wife was out running errands. Time to break for lunch.

While eating lunch & cooling down, I realized that maybe I hadn't screwed it up after all. You see, the wings have one side made with 3/4" ply glued into rabbets in the 2" x 2" posts, and the other side was designed with 3/4" rails, but which I had changed to 7/8" rails. So the two front notches shouldn't be the same length. So after lunch, I held that shelf up to the other wing & sure enough, the cut was spot on perfect. Whew!

At this point, I abandoned laying out the notches. Instead, I just set my combo square for the length of the notch in question, put the body against the edge of the shelf & adjusted it so the end of the ruler touched the edge of the aux fence. Then I put a spring clamp on to hold everything in place & made a pass. Then I nibbled the rest of the stock away for that corner.

This worked very well. Due to the solid edging being wider than the ply's thickness, I couldn't do both front notches with the miter gauge in the same slot. I had to move it to the other slot & remount the fence to get the other notch done. I fumbled the order of cuts & had to do that about 2 or 3 times. But I got them done.

I had to do a little clean up with my chisels & some sand paper since I have an ATB combo blade mounted to the saw. And this did take all day. But I was feeling a lot better about the shelves.

The next day, a Saturday, I got started on the right wing. I disassembled it & did all of the items on my list for that wing. I drilled holes in the top shelves for brass cup holders. I drilled pocket hole screws in the top & bottom shelves to draw the posts in tight after assembly. I re-drilled the shelf pin holes, and drilled the two missing holes in the post that needed them. I sanded everything with my ROS & with 180 grit paper by hand.

All of this took a bit longer than just that Saturday, but it was time well spent. And when all of it was done, I did one last dry fit to see how & in what order I'd put everything together. All set for doing it for real!

I got home from work on Tuesday & I glued the end panel together. This took longer to do than I thought it would. Unseen checks in the stock that I used to make a couple of the stretcher / shelf supports in that wing caused the wood to split pretty badly when I drove the pocket hole screws home, so I had to remake those. This time, I used ply scraps & ironed on some red oak edge banding I had left over from my DVD cabinet project to hide the ply edge grain.

I put it together on top of my table saw (I did put a drop cloth on top to protect the cast iron from glue drips). I squeezed a dollop of silicone caulk on to the edges of the raised panels & buried a Space Ball in each one. Then I spread glue on one tenon of the bottom rail & put it in place, carefully aligning it with the bottom rabbet on the post.

Next the bottom panel went in, then the middle rail, followed by the top panel & lastly the top rail. I spread glue on the tenons & in the mortices & put the other post on. I used three 24" K body clamps to pull the assembly tight. Next I spread some glue on the ends of the bottom stretcher and the edge that contacts the bottom rail. After using my spacer block & clamps, I drove the pocket hole screws home for the last time. Then I spread glue on the ends only of the top stretcher (this one doesn't contact any rails) and screwed that in place.

I had to put a long clamp vertically across the front of the assembly to get the top & bottom rails in their proper places, even with the ends. I finished up at about 9:00 pm, which is my usual knock off time when I work on a week night.

I'm happy to say that the assembly came out flat and square. Praise the Lord!

The next night, I worked on the final glue-up for that box. This consisted of gluing the bottom shelf to the bottom stretcher, keeping it square, and driving screws through the stretcher into the shelf. The front bottom stretcher was then glued & screwed to the bottom of the corresponding shelf edge, and then a pocket hole screw was driven into the post. Pocket hole screws were driven into 2 pocket holes in the front shelf edging (which is 3" wide). I then repeated this process with the top shelf, which used 1 fewer pocket hole screw.

At this point, it's time to attach space balls with caulk, spread glue on tenons & insert the rails & panels. This is the stressful part of the glue up, since you have to get the glue spread on all of the joints & everything put together & clamped within the glue's open time.

I got it done. I was busy working on it until 10:30 that night, but I got it done.

I then started to work on the center box. I took the box apart. I cleaned up a few gouges. I re-drilled the shelf pin holes. I even glued the bottom rail into one side. I did this because I had some trouble getting everything square & I thought having this glued into one side before doing the full glue-up would eliminate this issue.

Then I tried to do a dry fit. And I found that the panels I had made for it were 5/8" too wide! This meant that the top & bottom rail were 1 1/4" too short, and the center rails were 5/8" too short. Time for some more cursing. Pack it in for the day. And figure out how I'm going to fix this one.

Thinking about it, I saw I had two ways to fix it:

  1. Remake the rails longer
  2. Cut the panels narrower & refinish them.

Option 1 meant I'd have to cut out the bottom rail I had glued in previously and throw away the parts I'd already made. Not really desirable. Option 2 meant I'd have to strip the finish off, cut the panels narrower, re-route the raised profile, then refinish everything, matching any finish I'd left on. I found this idea to be daunting -- I'm OK at finishing, but it's not my strength.

At this point, I contacted Neil Lamens from Furnitology Productions via email to ask his opinion. He recommended I cut the panels down. His reasons were sound -- keep the project moving, and remaking the parts is expensive. I would have to buy more lumber. And machine set ups are difficult to repeat.

In the end, I decided just to remake the parts. Since this piece is being made as a donation for my church, the usual economics don't apply. I can just include the costs for the additional wood in the value of the donation at tax time. And frankly, it would take me a lot less time to remake the parts than it would be to just strip the panels down.

So I went out out & bought another piece of lumber. And I put the center box aside & put the other wing together. I needed to let that wood acclimate after all, and putting the other box together would help to keep some of the momentum going. Besides, I'd have to change the set up on my plunge router, which was set up to do shelf pin holes, and I didn't want to do that until I was done using that setup.

This one went together well and a little faster, having had the practice from the first box. While I was at it, I also drilled the holes for the bolts & the threaded inserts that would hold the finished boxes together. Here's a picture of the two boxes with the sides of the center box attached to each box.

The two boxes are about as far apart in the picture as the center box will be wide when finished, so you can get a feeling for how big the finished pulpit will be.

That's enough for now. Part 2 will follow soon.