Monday, 19 December 2016

Resin and other disasters

I'm not sure if I should laugh or cry but I've had a good go at producing some resin goodies, and may have learnt a few things along the way. I read a few posts on resin casting and watched some videos on Youtube.
I found the official video and cannot see that I'd done anything wrong.


However my hunch that the problems were to do with heat was backed up by a few things that I had read. One suggestion that I found suggested that post heating might help to cure the resin. So Saturday a week ago I thought that as my partner was working it would be a good time to test out post heating in the oven. I was being careful and found an oven tray which I turned upside down and then covered with tin foil. The idea being to avoid any contamination.  I preheated the oven and started to do some vacuuming which was the days chore. After about ten minutes I put the resin on the tray and intended to come back in 10 minutes to check on progress. Well it was almost like 20 minutes when I looked up from vacuuming and noticed black smoke coming from the oven. Panic time!!! first I turned off the oven then opened the oven door. I rushed to the conservatory to open the large sliding door to let some air in and then went to see what had happened to the resin. Much to my surprise nothing really except it looked a bit curled. I grabbed the whole lot and then put it on the back step and spent about half an hour trying to get rid of the smell while trying not to breath anything in. I also finished off the vacuuming. After that it was still a bit smelly so had to open the front door and put a large fan in the hallway to move some air around. Of course by the time I'd finished this the wind had changed and it had started to rain so I went outside and picked the now wet resin off the grass which was where it had blown. I then stuck it on the top of a cupboard and ignored it till Sunday. When my darling came home everything was back to normal with no smell. Presumably if my brother reads this he will drop me in it over Christmas.

Sunday I checked the resin and found that it was really hard but curled. The primer was still sticky on most of the items. I thought I'd have a go with bending the resin with hot water. First few attempts were good as I had selected the best pieces but found that the water went cold too quickly. I then thought up a way of keeping the water hotter for longer by filling a stainless mug with hot water and then sitting it in a bowl of hot water like this.


This worked really well which meant I could go on and reform all the pieces in one go. A bonus was that the primer had also stopped being sticky. I had a couple of spares that obviously were never going to work as they had resin oozing out so these were dumped. I set everything aside and went and did some gardening. Later on I came and checked the pieces out but to my disappointment found that they had all curled again and the primer was sticky again. I muttered to myself that this was not worth it and put everything in here. (quite calmly)


My thoughts on this that too much time had passed which meant that air and moisture had gotten into the resin. I thought that the time taken to do this was longer than doing it in plastic. However I still had some decent moulds and plenty of resin. I had a test run with thicker depth on the window and used the left over resin to make some ammo boxes. I also had to use the lego boxes to give greater depth and preheated everything with a lamp and then used the lamp to heat the setting resin.



Look at the colour, this looks like professional moulded resin and the details are so crisp and square. I am going to start over and remould everything over the Christmas break while the weather is warm. I still have to work out the correct amount of resin to pour as the window is way too thick and wide so I need to shim the mould. 


At this point I am very happy and am planning on doing some other casting, but first I have to finish these houses.



3 comments:

  1. Wow! You had some bad luck with those pieces. I cast some resin models the other day. The resin is old but still works, except when it began to cure it developed a head of foam a pint of Guinness would envy. I scraped it off as it bubbled up until it hardened. The pieces are fine, if a bit lighter than usual. I put it down to the cold.

    ReplyDelete
  2. I have seen something similar, if it is too cold the resin will not cure properly and remains sticky. It needs to be fairly warm, the spec sheet should have a temperature range. Of course if it gets too warm then it cures too quickly.

    ReplyDelete
    Replies
    1. I suspect that the room I was working in was warm enough but, the product which had been sitting on the floor was much colder. I've had much better results when both were warm but still had a bad pour on one occasion.

      Delete