Disaster Strikes - And some fun with saws

[Michael J Gardner]

The Disaster

So I finished 3 coats of BLO on my tabletop, waxed it, had it looking (and feeling) great. I decided to take it into the house to make sure that it didn't "move" to much in it's final environment. This gave me space in my tiny workshop to start on the aprons. After the table had sat for a week on my coffee table, this morning I hear a tearing sound and my heart sinks. I walk over to my table top and immediately see the issue. The glue up on the middle boards has failed on the very ends, leaving an ever so tiny gap between its two front teeth. The house is 30 degrees warmer than the workspace I built it in. I was hoping that it wouldn't shift or twist like crazy once it was introduced to the warmer environment but I was wrong. There was also some damage on the last board, which was the most figured of the 4.

Joint splits:
split-1.jpgsplit-2.jpg

Grain split:
figured-tear.jpg

Before the "event":
table-test.jpg

I'm going to let it sit for a few more weeks and see if it moves any more. My plan is to wait till summer, take it back outside, then try to do a repair. I'm not sure if the best route is to epoxy the spots, then plane the entire surface flat again and refinish. Or perhaps rip down the entire center seam, rejoint and do a fresh glue up. The epoxy would be a faster fix, and take less time repairing the bevels on the end.

The Fun

So today I took a break from the table and did some shop chores and random improvements. One of the things on my list was to fix up the saws I've been collecting.

First is a 'Warranted Superior' Panel Saw that I picked up at a flea market a few months ago. The saw wasn't chewing through material the way I wanted so I decided to give it some tender love and care. After a lot of research, I decided that the problem was both the set and the rake. It was 4 TPI but I had originally set the rake to about 30 degrees when I did the initial refurbishment on her. I grabbed a file and put 0 degrees of rake on it, except for the first 4 inches where I progressively took the rake back to 30 degrees. Then I put an aggressive set on the teeth and tried her out. She now tears through wood faster than I thought possible, with little effort.
warranted-superior.jpg

Then I moved on to two Disston backsaws that I had picked up from another flea market. Both are 12 inch, probably about 14 PPI. One had a polished steel back, the other blued steel.

The first was a user. The plate had almost half an inch removed from previous use. The plate looked slightly bent so I used the slap technique on a flat surface to try and seat it properly. Problem fixed. The handle was well worn but no damage. I gave it a quick tune up by jointing and then resharpening for rip and putting on a very minor set. She sang true and had zero issues when I did a few test cuts.
dovetail.jpg

The second was a bit more interesting. It was never used? The plate was in great condition, the bottom of the plates have a heel on them, and it was complete. I doubt it had ever been sharpened. But like all things that look to good to be true, there was a reason for this. I did a test cut and it bound up immediately. I checked the plate and there was a slight bend in it. I did the slap trick but it didn't change the bend in the blade. So I took her apart. Once I had the plate out of the folded back (wow they were a tight fit), I checked the plate and it was perfectly flat. That left me a bit worried because if the issue was the back, I doubt I could fix it. I cleaned up the individual pieces and then re-assembled. I took a lot of care to not put to much tension on the blade with the nuts, and get the back in a position equal to the 'user' Disston I had just worked on. I sharpened her up, put on a light set and then took her to a test cut. She cut well but still wanted to shift slightly left. A huge improvement to binding. I took a file to the left side of the plate and took some slight set off the teeth then tried again. Success! In the picture I have several of the test cuts, they were perfect.
carcass.jpg

[John C Cox]

Ouch! Sorry to hear about that. I found it was worthwhile to heat my shop while I'm working on projects. The good thing is that it runs the relative humidity down low. Generally, stuff built in low humidity won't crack to pieces when it gets into a space with higher humidity like it will when you go the other direction.

[Jim Koepke]

Michael, I think the splitting on your table top is why some people advocate sprung joints. I haven't had much problem with joints splitting, but much of my work is in softer woods like fir and pine.

Nice job on the saws.

jtk

[Michael J Gardner]

Yeah that might be the answer. Rip the joints this summer, re contour them as spring joints and redo the glue up. It’s the right way to do it, rather than slapping on some epoxy. A fix for the problem, not a band-aid.

[Tom Bender]

Not sure about spring joints. That's a lot of wood to bend the hard way. Looks like the problem is shrinkage from drying faster at the ends. You might have a better result by applying a coat of polyurethane varnish just to the end grain.

Can you explain slapping a saw straight?

[John C Cox]

Yeah that might be the answer. Rip the joints this summer, re contour them as spring joints and redo the glue up. It’s the right way to do it, rather than slapping on some epoxy. A fix for the problem, not a band-aid.

Unless you're in a very dry summer climate - Arizona, Nevada, parts of Colorado, etc... Summer can be a worse time to redo joints like this, as the relative humidity in the shop is even higher than it is inside the house in winter.

Not sure where you live, but most of the midwest had a brutal cold spell thus winter, and inside was 80-90 degrees warmer than outside. That pushed indoor relative humidity down to ~0. Wood shrinks with low humidity. Lots of stuck doors and drawers. Lots of cracked furniture. Lots of bloody noses and cracked skin.

Nobody likes this strategy, but leave the cracked stuff in the house. Let it acclimate in the dry. If at all possible, rejoint it once acclimated inside your house, but while it's still good and cold outside. Or, punt. Make a sliding expansion joint there, say incorporate an add-a-leaf, or some such.

[Michael J Gardner]

I'm thinking Summer because currently I'm up in Maine, and eventually I will be moving back down to South Florida where I'm originally from.

It certainly has been a good learning experience, I just wish it wasn't so cold outside. I've been cutting practice draw-bore mortise and tenons out of pine in the workshop but it's so darn frigid. My blood is still too thin for this weather.