Epoxy resin river laptop tray
For the longest time I’ve wanted to play with epoxy resin. Watching makers like Peter Brown, Ben’s Worx, and TheCrafsMan on YouTube inspired the desire to use resin in a project, and conversations with my patron, Emma, revealed that she had similar desires, so during the first weekend of February she joined me in my workshop, and powered with nothing more than imagination and ill-gained confidence, we decided to make an epoxy resin river laptop tray for her husband.
The journey to this fated weekend started back in mid-Janurary during a trip to Bristol. Shortly after Christmas, Lucy and I decided we needed new Superdry hoodies, so a trip to Cabot Circus was planned. Little-known to Lucy, Bristol was also home to the Bristol Wood Recycling Project, and there’s no way that I was going to skip visiting a reclamation yard if I was in the neighbourhood.
I walked out £150 poorer with one cherry, and two sycamore, waney edged boards under my arm.
The cherry and £38 sycamore boards were for me, but the £45 sycamore was for Emma, chosen from the vast selection of amazing boards, via WhatsApp consultation and lots of photos.
The reclamation yard had a lot to choose from, with most of the waney edge boards being rough sawn, and over two-and-a-half meters long, but they had a small selection of boards which had been cut down to size, squared off, planed and finished with oil, which they were selling to be used as shelves. These were perfect for my purposes, as I don’t have a planer/thicknesser (something which is going to come back and bite us in the arse shortly).
Next we needed the resin. I’d decided a while ago that I was going to use GlassCast resin because they’re British (I didn’t want to mess about importing stuff), and because of all the helpful tools and information they have on their site, specifically the video tutorials they have for a number of different resin projects, and the resin calculator to work out how much resin you’ll need for the different projects featured in the videos.
I had planned on using my cherry board to make a river table for myself, but the calculator revealed that I’d need just under 5kg of resin at a cost of just over £80 for the resin alone, and as I’d already spend all my money on my new Superdry hoodie, decided I’d shelf the idea temporally.
Price wasn’t a barrier for Emma, however, and £130 later I was awaiting shipment of 2kg of resin, a selection of metallic pigments, a roll of flash/release tape, a 100x100cm polypropylene sheet, some nitrile gloves, and some mixing cups.
Emma arrived on the Friday, and after a night of catching up (and drinking), we awoke Saturday morning ready to work.
The original plan had been to split the board into three sections, with two of them being individually squared off using resin, but after some thought we decided this was going to be a bit too difficult, mainly due to having three open edges against the resin, and not really being sure how to make a form to contain it all.
So we went with plan B, which was to go for a single piece featuring the more traditional river table approach of two boards facing each other, so after cutting the board down to size, we set about using two offcuts from the door in my basement and some clamps to create a makeshift form on top of the polypropylene sheet, sealed around the edges with (far too much) silicone.
Next on the agenda was preparing the resin. Emma wanted it to be olive green, but that wasn’t available as a pre-mixed colour, so instead she took three parts yellow pigment, one part blue, and a touch of red, and combined it until it was the perfect colour.
Based on our calculations we knew that 1kg of resin should be more than enough to fill the gap, which made mixing the batch easy, so after pouring all the resin from one bottle into the cup, and mixing the pigment into it, we then poured the hardener in, and mixed it some more. I’d picked up a paint stirrer which fits into your drill to the mixing process easy, but we’d decided to use the two-cup method of pouring all the mix from one cup into a second just to be sure everything was thoroughly mixed.
I was given the honour of pouring the mixture into the gap, which reached the top with ease, but after a few minutes, we’d noticed the level had dropped off, so poured in some more. We figured this shrinking was probably due to the bubbles in the resin (the resin has a fairly long open time, so we could have waited a while to let these rise to the surface before pouring), but little did we know the real cause.
We could see the level was still dropping, but had already used the remaining resin mixture and filled a knot in one of my planks, so decided that we’d top it off with clear resin the following day, so after a couple of hours of monitoring the situation to ensure there were no leaks, we called it a day and resumed drinking.
The following morning we were greeted by a few small leaks in the form, but thankfully, the resin had already hardened enough to plug them.
We proceeded to mix the second batch of resin, and as we’d left it clear, we could see all the bubbles slowly rise up and out of the mixture. Having watched lots of videos about epoxy resin, I knew that bubbles could be an issue, and that you can use a pressure pot or vacuum chamber to eliminate them, so to watch them remove themselves from the equation was something special. I don’t know if this is a feature unique to GlassCast, but it’s impressive all the same.
Content that we had done as much as we could, we spent the rest of the day exploring Springfair, before Emma had to head home. If we’d have read the technical sheet sooner, we’d have seen that it takes at least 48 hours for the resin to cure, but I was happy to finish up by myself in the week.
Fast forward to Tuesday and I was ready to de mould. The first thing I did was turn the form over, and discovered where the resin had gone.
As mentioned earlier, I don’t have a planer/thicknesser, meaning we had to use the boards as they came, and it seems they came with some warping in them, enough that neither board sat perfectly flat on the polypropylene sheet, letting the resin seep under them.
Job one was freeing them from the supports. If we’d placed the tape along the full length of supports we could have simply lifted them off, but because we hadn’t, it meant cutting them of with the table saw.
Job two was removing the resin amassed on the bottom. I asked around to see if anyone had a planer/thicknesser, but the only one I had access to was too small, so I had no choice but to sand it off using my belt sander.
I then switched to my random orbit sander and went up to 400 grit. This left the river section of the resin on the bottom cloudy, which I could have continued sanding up to 3000 grid and beyond, then use some polishing compound to make it glossy again, but I don’t have any of those things, and was well aware of the Valentine’s Day deadline, so decided that because it was on the bottom it was good enough for now.
Flipping the board over, the top was pretty good as is, being naturally nice and glossy. There’s a slight drop of less than 1mm, but not enough of a concern to make it worth sanding the wood down at the risk of messing up the gloss, so I carefully gave the wood a light sanding, being sure to avoid the resin at all cost.
And for now, this is where this story must end. I’ve sent the board to Emma, who will give it to Pete on Valentine’s day, to let him decide what happens next. One idea is we maybe trim it down slightly and keep with the idea of a laptop tray, another is we add some handles on either side and make it into a serving tray. Regardless of what happens next, it isn’t the end of the adventure, just a pause, and when we return, we’ll round over the edges with a router, polish the bottom and sides, and reveal it’s final form.