Making a base for a heavy glass art piece

I'm posting this in case it helps anyone find a solution to making bases for awkward glass artwork.

Whilst preparing my work for display at Doddington Hall I had a bit of a mad panic and had to quickly solve a problem that could have led to me not displaying a major piece.

Essentially this came about after re-polishing Anthropomorphized Waves II a second time. I originally polished it and exhibited it at the National Glass Centre for my Degree Show in 2018, then decided to re-polish it and remove some final scratches, packaged it in a crate and it has been sat inaccessible for 2 years whilst I have been trying to cope with health issues and renovate my studio.

After finishing building my raised flooring I managed to get the artwork out to check it prior to exhibiting and noticed that it was not fully flat underneath which could potentially have led to problems since it was to be displayed outside.

After discussing my options with several people I had really only one choice, to build a wooden base for the piece. I had not yet sorted out cold-working equipment to re-polish it flat and even then, due to the size and weight of the piece and the fact that the glass is very hard it would have still been hard to do so.

I had the idea to try and cut out a sheet/block of wood that could fit either entirely round or have a shallow excavation around the existing glass foot and then laminate / dowel / screw this to another piece to form a flat base and glue it in place.

After asking many people and coming up short on whether or not my idea would work and even shorter on anyone that wanted to make it, I eventually found help and advice from chainsaw sculptor Mick Barnes in the next village who lent me a tool for chasing out a rectangular shape for the glass foot and also cut me some spare 40mm Sapele wood for the base using his table saw.

He suggested making a two-tiered base to give a better aesthetic for the piece and also suggested making a hole in the base so that lights could be placed in the piece (later).

I glued some paper to the bottom of the glass foot and traced around it to form an exact template and placed this centre of the higher tiered wooden base. We'd already used my measurements to estimate the size needed for the foot with 1" clearance around the glass.

I then chased the inner part of the outline using the sanding belt tool. Although this was a standalone specialist tool, similar adaptors can be used that fit to angle grinder and can be purchased on ebay for around £30-£40 (In retrospect these adaptors aren't as good as the belts tend to slip off easily). I was using zirconium corundum belts 1cm wide which were very quick at removing material and left a good finish.

I then widened the chasing to cover the rest of the inner top area. In order to keep the functionality of the piece (being able to light it) I then used a scorpion saw (after drilling holes for the blades to fit through) and a jigsaw blade to cut out part of the inner section. This was tough going so when it came to making a hole in the bottom wooden base I used my biggest drill bit to cut several holes to remove the middle and then neatened this up with the sanding belts and a mouse sander.

The bottom part of the base was measured and cut to give another 1" around the outside bigger than the top piece.

I aligned the two pieces of wood and clamped them together before drilling holes fully through the bottom wood and 2cm into the underside of the top wood. I then cleaned up the wood with white spirit, let this dry and then applied a coat of Ronseal Satin Yacht Varnish to each piece.

After giving this 8 hours to dry, I scored the wood where the two sections would fit together and applied PVA to them before screwing the sections together.

In order to glue the piece to the base (using clear epoxy resin), I inserted approx 1kg of plasticine into the hole and flattened this off. I then added a raised plasticine part on top of this to hopefully keep the resin from touching part of the base so it would be clear and able to transmit light. Due to the slight camber of the piece's bottom I was advised to use some colloidal silica in my resin mix to help thicken the glue and level out the base. I did a test of this using a resin I had in stock to gauge an idea of how much would be needed and to check that my resin would still set and it did fine.

After using a diamond cutting wheel and a dremel (equivalent ) tool to score the glass base and provide a key between the wood and the glass, I stirred the resin mix thoroughly and filled the entire chased out cavity. I then stood the glass piece in the base and propped it upright with bags of clay. Naturally resin overflowed but I had a continuous roll of plastic polythene dust sheet and had cordoned off my studio floor and around the base. I pulled this off at the time to limit the chance of it sticking to the base or to the glass and wiped up excess with paper towel. I also used some of the resin to fill a slight gap between the two pieces of wood and then left this to set overnight until late the next day.

I used a mouse sander to remove some overspill resin off the base sides and then wiped down with white spirit before applying a few more coats of varnish (letting each coat dry separately). I removed the plasticine by hand and with pottery tools. It had done its job well but was a right pain to remove completely. I varnished inside and also cleaned up the resin using a hammer and chisel to remove any sharp pieces. The middle had stayed clear and the although the outer part was an opaque-white colour it still transmitted light.

I then cut out some of the high resistant packaging foam in the ready-made crate to make room for the new base.

I also added gel pads to the bottom of the piece where the screws attached to raise it slightly from the plinth so if it rains it won't be sitting in wet and the water can evaporate.

I also had a backup plan which I decided wasn't needed in the end. This was to use fence brackets that could be screwed into the plinth to hook onto the top of the base if needed to keep it stable and would be exactly the right size (44mm) when combined with the gel feet and the thickness of the lower part of the wooden base.

Delivery and installation of the piece at Doddington was a great success. I took one of my scissor lift trucks with me and this made it all the easier to pump up the artwork in its crate to the height of the plywood plinths before the delivery driver and his helper and me lifted them into place.

I used L F Connell & Son who have been very helpful and professional.

After that, all that was required was to pick out any small foam material and give it a clean with glass polish.

My other sculpture Anthropomorphized Waves I was flat underneath and although I made an oak base (using the same method), I decided not to use it in the end as could not lift the artwork to secure it to the base and it was not as necessary as the other pieces' base.

I placed small amounts of museum gel under the sculpture (Anthropomorphized Waves I) just to help it stick to the plinth slightly. It's worth noting that this isn't meant for outdoors and can liquefy in extreme heat hence I didn't use much. Luckily the weight of the piece and hole in the centre is enough to keep it securely in place and it withstands the wind fairly well.

Other options that I may consider using in the future are making metal bases with threaded bolts protruding off the bottom to either be mounted into the ground or secured on the underside of a plinth, although they will still require being adhered to glass.