This project is about making some random-layout end-grain coasters.
These are made in much the same way you would make end-grain cutting boards. However, one key difference is that you arrange the pieces in a purposely random arrangement, and not in a nice even regular layout. (and yes, "purposely random" is a bit of an oxymoron, isn't it?)
Step 1: Option: Video Build
If you would prefer, you can watch a video of this project build. Otherwise, read on!
Step 2: Pull Out Your Small Stuff, But Mind the Colours!
This is the time to pull out all your small and thin strips of wood that you have been saving. In fact, you may end up making a cutting board or two at the same time -- I did. We woodworkers always save these "too-nice-to-throw-out" pieces, so now we can make good use of them.
I first made a set of these coasters several years ago. I pulled out my wood, and glued pieces together, then arranged them, and glued some more. I worked very hard to make a nice random-ish arrangement and I thought it was working out very well. Then I sliced them up into coasters and put on some finish .... and they were DULL. The problem was that I had used maple and oak, and even some yellowheart, and there just was not enough colour and contrast. They looked bland.
So I started over and this time made sure to include just a few pieces of walnut and padauk (or jatoba, I forget which; it was red!). Here in the photo you can see the original bland pieces being compared to one of the pieces with contrast. It doesn't even have finish on it, but it already looks far better than the others.
Step 3: Lots of Gluing and Clamping
I laid out my pieces, sorted through them, and started gluing them up in chunks. In the photo you can see some really short strips of padauk on the table. With a project like this you can use up really small pieces such as those. Coasters are small, so if you end up with a blank the length of the one in my hands (in the photo) you would be able to get two or three sets of coasts out of it.
So you can even use short pieces, such as the ones on the bench, and just glue them end to end. Odds are the joint will fall in the middle of a coaster and you'll never see it. And if it is visible, just set that coaster aside. Later on you'll see how I sorted out the reject coasters from my project. Plan on having a few and make sure your blank is long enough to accommodate some waste.
The second photo shows part way through the process of gluing up a blank. I would glue up 4-6 pieces, then joint them and clean up the edges, and then glue them together with another different sized piece. Sometimes that other piece is itself a blank of glued up pieces. I try to orient them differently each time, but it is often a challenge to make sure that you end up with something that is still square enough to glue to something else.
Step 4: More Gluing and Clamping
Here I have glued on a piece and I am carefully scraping any glue squeeze-out from a 90-degree corner. I want to make sure that the opening is clean so that I can fit in another piece later on in the process.
Step 5: Finished Blank
This is my finished coaster "blank". This took me about a week of evenings to get to this stage. (I could have pushed to get it quicker, but this is still a hobby so I just work in my spare time.) My goal was a coaster that was 3-1/4 inches square, so the blank had to be a bit bigger than that. I could then clean it up on the jointer and rip it square on the table saw.
Over on the bandsaw I set things up to make a cut of between 3/8" and 1/2" in thickness. If it is too thick, it is just too unwieldy as a coaster. But if it is too thin, then I am concerned that it could break too easily. The glue joints are mostly all nice and strong long grain joints... but they are also pretty short. So I think you could snap them without too much effort.
After slicing a bunch of coasters, I sorted through them looking for any defects. I found two that had a partial knot showing, and one with a broken chunk on the edge. This is why I made the blank large enough to have extra.
Step 6: Sand Sand Finish Finish
I put a 120 grit belt in the stationary belt sander and used that to smooth the face of the coasters. It only took a few seconds per side to produce a nice smooth surface. I then used a Random-orbit sander to smooth the sides and corners.
I applied several coats of polyurethane. Coasters will inevitably have wet glasses placed on them at some point, so you want the water-protection of a film finish like polyurethane.
After the first coat of poly, the grain was raised a bit, and I sanded the coasters with 220 grit sandpaper. After the second and third coat I sanded with 400 grit.
Step 7: Compared to the Bland One...
Here are the finished coasters, compared to the original "bland" coaster from a few years ago. I think you can clearly see how much better these look with all the contrasting woods.
Step 8: Photo Gallery
Here below are some more photos of the finished coasters.
(This includes one photo showing the blank and an unfinished coaster slice.)