Planed Finish VS Sandpaper - Microscopic View

[Mel Fulks]

I don't know enough science to say Patrick is not right, but tests frequently show no problems with glued joints on planed wood. Without failures what concerns can there be? Machine planed surfaces vary a lot just from different steels. Even with the lowest quality steel ,which is the most used, the glue manufacturers only warn about joints glued on surfaces not freshly cut.

[Shannon Cuffe]

Hi guys, I have been watching this thread with keen interest. There has been quite a lot of good information given. I have been in the trade for 17 years. I have used a myriad of different timbers, glues and surface preps. Glues ranging from TB supreme, TB original, TBII and TBIII, polyurethane, koyobond, resorcinol, and urea-formaldehyde. regardless of how I prepare the mating surfaces, the only time a glue joint fails is when I am being a lazy numbskull and attempt to join two convex faces. The harder woods split at the ends everytime, usually within the first month. Softer woods seem not to care so much.

The only difference I have seen with particular surface preps are
- sanding = fat glue lines due to the dubbing of the edges
- sawing - occasional chipout on the bottom edge due to the sawing action (it can be planed/sanded away but it is just more work)
- handplaning = probably the best/thinnest glue line
- machine planing = very similar to a handplaned glue line. it is probably slightly fatter than a handplaned joint.

So I do machine planed joints more often than not because most other preps (for me) are another step after jointing on the jointer.

[Van Huskey]

It always intrigues me that the most hand tool oriented spend the most time dealing with the micro-science of woodworking.

Interesting discussion.

[Derek Cohen]

Gad, there is too much over-thinking here. The only time I have experienced a panel come apart at a handplaned edge is when I starved it of glue as a result of over-tensioning the clamps. 20 years of jointing with handplanes and only the single example. Glues used ran the range of Titebond products, including hide glue, and epoxy.

Regards from Perth

Derek

[Stewie Simpson]

Its an interesting dilemma, much more common on this forum than any other I regularly frequent. Its genesis imo started off with a long and heavy discussion on the merits of bevel up bench planes, then veered right with the expanded choice of alloy steels on offer within chisel and plane irons, then veered left to the benefits of synthetic over natural honing stones, to where we are at this given moment, talking about a machined surface vs hand planed surface vs a sanded surface. Its difficult to speculate with certainty what the next high focus agenda might be on the near horizon. Possibly the type of colour that the manufacturers spray their hand planes, and how that can make a huge difference to your woodwork. Could Engine Black be soon replaced by Canary Yellow. Cant wait. I need to stock up on the popcorn.

Stewie;

[Curt Putnam]

Patrick, Thank you for the clarification. Was nervous for a while.