Background: I work at a woodworking shop, doing design etc. and both myself and a colleague sometimes do personal projects using the tools, machinery etc. here in our own time. These projects are typically not for personal gain and often end up being gifts for friends, family etc.
A long time ago (a few years) I showed him this table that I had found, and talked about making one, possibly using poured resin rather than different layers of glass.
More recently he has begun talking about doing something with resin, more similar to this. It's a different design but similar in that it still involves poured resin.
Neither of us have any experience in working with resin before, but it was brought up again last week and I basically said "you know what, I'll just buy some and try it to see if I can figure out how to work with it". I bought a small amount and did just that. Since I bought it, my colleague has been being quite short with me. I thought he might just be in a bad mood in general, which happens sometimes.
Yesterday at the end of the work day I stayed a short time after hours and mixed a small batch of resin to harden in the pot just as a test. Before doing so I asked my colleague if he would like to come and "mess about with resin" since I knew he was interested in it, and he said no, so I went ahead and did it.
After I'd mixed it, I knew I needed to leave it overnight to cure to see the results. I went back into the office to get my things before leaving for home and my colleague was in there, working overtime.
I made a brief comment about how the material was to work with and all I got back was a sneer. I asked if he was annoyed that I had ordered resin and the floodgates opened. He stopped short of shouting at me but he was quite aggressive. He said that I had "stolen his excitement" about working with resin and that he'd now learned to keep quiet about any of his future projects. I was taken aback. I apologised and said that it wasn't my intention to do that. If the roles were reversed I would feel interested and excited to see his results with the material and I did not foresee that he might feel the way he does instead.
He ultimately said "don't worry it's a thing with me, not with you" and walked off, closing the door behind him. Regardless, I do feel bad. I'd like to pursue things more and try to smooth things out a bit, since we've been friendly before and occasionally done things outside work together like playing sports. How should I go about this?
For further context I sit about 8 feet away from this colleague in an open plan office. We don't need to talk very much but do need to interact from time to time. He's been civil enough with me so far today but I sense he is still annoyed and I would like to avoid too much bad feeling.
I intend to continue experimenting with resins but I will likely keep this hidden from my colleague and not discuss it with him.