Sep 19

Scraping resin

I don’t know why I had it in my head that you couldn’t scrape resin and you had to sand it, but I did. And it’s not a great approach. I poured a little extra over the last day’s resin pour to get it proud of the surface, and ran both packing tape and a hot glue dam around the edge to let it get proud without spilling all over the place.  

Pour, let it cure, remove hot glue with ease, curse and swear for half an hour or more while removing the packing tape because it doesn’t want to remove cleanly. Scrape with the plastic razor blades to get the last of it up. 

Total pain. Worse yet, you get a perfect surface when you pour it but you know you’ll have to destroy that to get a single flat plane for the tabletop 🙁

Oh well. 
I don’t have many photos of the next step which was to take my new sander and try sanding all of that down to flush with the surface starting at 180 grit and progressing up to 500, 2000 and 2500 wet&dry, which took forever, only to misalign a sheet of paper near the end and not cover the velcro hooks on the bottom of the sander and grinding these small circular paths into the surface that I couldn’t polish out. I resorted to pouring even more resin to fill them in, and then trying to sand that back down again and finally just losing patience completely and taking a card scraper and a #080 to the thing.

I don’t know why I didn’t do the scraper first. It was far more effective than sanding. I mean, I still have to sand after scraping because that surface isn’t great, but the problem with sanding is that resin dust is white. That’s why the walnut looks like someone spilled talc over it there. I tried flushing it out with white spirits, pulling it out with tack cloths, nothing worked. Rather depressing. What I’m hoping is that the finish will “wet” the dust and keep it that way. When it’s wet from white spirits, it looks fine. 

So while I’m going to put a poly surface on as the final coat, I grabbed some danish oil and thinned it with white spirits and hopefully that will penetrate down into the pores and cover up the mess.

Not bad. It cured slightly lighter, so I put another coat on it but it looks pretty okay. I mean, I’m not done with this yet, I need to either sand or scrape the entire top again to clear up some small defects and I still haven’t shaped the edges – those sharp edges can’t stay, they’re only there so I could manage it better while doing joinery and inlay and so on. But that’ll be one of the last steps. I’m done with this board for now, I’ll put a towel on it to protect it and set it aside.

The next job is going to be routing the next shelf up so I can have an LED light recessed into the underneath of it to light the desk. I’ll have to order an extra-long drill bit to get the cable to the recess from the rear, and then I can use the router to chase the cable through the back of the shelf and the uprights so there aren’t any dangling cables.

And I’ll think about putting some inlay on those boards and the sides as well. And I’ll have to take the sharp edges off too. And then I can assemble and finish. 

Aug 19

Pouring the sea

So the next step was to even out the bottom of the sea a bit with the router. That took about five minutes and was mostly making light cuts here and there rather than any systematic grid pattern thing. 

Then time to seal the grain; I don’t really want the resin leeching out through the grain. I mean, it’s walnut, it’s not very porous but still. 

This stuff isn’t wood filler, that kind of putty I use to cover my mistakes, this is much much finer grain material that is supposed to get into the pores and block them up. It’s a pretty thick mix in the tin, almost at a putty consistency, but you dilute it to a thin slurry with white spirit and then rub that into the wood with a rag, and clean it off when you’ve gotten as much in as will go.

With that done, it has to dry overnight. Oh well. Next morning, out with the reflective window film, and a fiddly job getting it to sit into a very irregular shape…

Looks fine so long as you don’t look too close…

But who’d ever do that? 😀 
Also, that film is self-adhesive on clean surfaces like glass, but forget about it being adhesive enough to stick to wood, especially if there are any irregularities. It’s being held here with a judicious application of CA glue. 
Then I started worrying about the resin adhering to the film and the film not adhering to very much at all…

So to let the resin seep into the walnut enough to get a grip, I drilled through the film with a 1.5mm drill bit all across the sea bed.

And I figured that was the ready-to-pour state. So I fetched a helper and we mixed up the first layer. Like we’ve been learning in Octonauts, the sea has three layers, starting with the midnight layer which is not only very dark but also hides the holes and gives a nice appearance of depth…

A bit of paint managed to not get mixed in the container so it got mixed on site…

Not too shabby. Left it for an hour, then came back to pour the Twilight Zone…

Not too bad, I’m liking how the layering is giving that differing depths look. The last layer was the Sunlight zone but that was after my helper’s bedtime so I had to pour it solo (I want the layers to bind as they set).

It’s almost deep enough here. One side was flush…

But one side was slightly shallow.

There followed fifteen minutes of tilting the board back and forth as the resin started to cure, to get a more even depth. Final result is even but still not proud of the surface and I want the resin to be slightly proud of the surface so I can use my new toy to take the whole surface to one contiguous plane…

I think the last bit will go down tomorrow evening, and then sanding can happen over the next few days. Once that’s done, that’s the walnut part of the desk done I think. I’ll think about how to decorate the poplar bits or even if they need to be decorated, or if I should just do the final shaping (the edges are all square right now to allow for easier handling but the final shaping will take off all the sharp corners and round everything over). Thinking about stuff. That’s the easiest bit of this hobby 😀

Jul 19

Adding the sea

So when the client for the desk likes racing cars and the Titanic, what do you do? You inlay a racetrack with stringing and banding and you add in a piece of the north Atlantic using resin 😀 
Step one: that router base will not let you get an even depth across that wide a hole, so unscrew it (mangling a screw in the process and having to use a left-hand screw removal bit to dig it out) and add on a much wider shop-made wooden base:

I’m willing to bet nobody else is dumb enough to use sapele for something like this (especially since plywood would be a better, flatter choice). 

Step two: strap on the respirator, the goggles, the ear defenders and make sure you’re good and uncomfortable from all the PPE even before you turn on the dust collector and the router and grit your teeth against the entire process and cut down about 8mm into walnut over a good third of the surface area of the desk, staying within the lines. Which takes a good hour to do because (a) this tool terrifies me and (b) everything is sooooooo slow in case it bites, digs in and pulls the bit through several weeks of work in the blink of an eye. Or, y’know, through me.

This still needs another last pass to even the sea bed out, by which time I think it’ll be 9mm down into a 21/22mm thick slab so it should still be stable, especially when the resin goes in. 

Before adding the resin though, I want to seal the bed and the sides with grain filler — not the wood putty type stuff, the much much finer stuff used to seal the pores (usually in oak) to stop finishes (or in this case resin) wicking through the pores in the wood and looking bad. Once that’s done, I’m going to add reflective film on the bottom of the sea bed. I tested this a while ago, if you do this and have a light source overhead, it lightens up the resin really nicely:

I may need to clean up the shed a bit before that though, every time I do any routing the shed looks like a small bomb went off in it and working there gets less pleasant.

Mind you, it can’t be all that bad, it passed the customer’s testing with flying colours…