Thread: My Wooden geared clock

Hi everyone.
I have started the process of resin impregnation of my Clock blank. I have used 2 x1.89 lit bottles of cactus juice to make sure that I cover the blank with at least 25mm of juice. I started the vacuum pump Friday at 5pm. There is still after almost 23 hrs quite a bit of air to go. Hopefully after 30hrs we will be down to 99% no air. Next will be to de-pressurise the chamber and let the blank soak in the resin. During the vac process you have high pressure in the blank and low pressure in the air above the blank. When we open the valve these will reverse and the air above the blank becomes high pressure and wants to go back into the wood but it cant because the wood is under a layer of liquid ie the resin. So the rule of thumb is to allow twice as many hours as it took to de-gas, to allow the resin time to be forced back into all those spaces in the timber that used to have air in them. Remember that the resin is much thicker than air and this is the reason why it needs at least double the time it took to remove all the air. Hope that makes sense.
Edit Its now 10pm and still going. I will check again 10am tomorrow: that will make it 40 hrs +...

Anyway getting closer to the oven phase.


Pic 1 My fan forced $100 oven






Pic 2 my blank under the cactus juice

Hi everyone.
Finally after 3 days I remembered that softwood are very difficult to resin impregnate due their cell structure. I decided to stop at this stage after I remembered that my trial blank was made from Radiata pine which is a softwood.
Anyway here are a couple of pics to help with that. You will notice that hardwoods have larger cells that alow the resin to penetrate more easily. I expect that the degassing time for my hardwood clock will be 24 hrs max. We shall see.
Currently the blank will now be left to soak in the resin bath for 7 days to allow full penetration of the resin.
More soon.

Dean.

After mucking around with my Bluetooth oven meat thermometer i discovered my oven jumps around a bit while trying to maintain the 200F that cactus juice requires. Anyway i have taken it out of the oven after 2.5 hours. I probably could have ended it sooner but i was advised to err on the side of caution. If you see any cured cactus juice on the outside of the blank then its all done. The internal temp of the blank needs to get to 185 deg + (hope I got that right) then the activation takes only minutes to finish. its cross linking.
The weight of the blank was 600g now it weights 1.3kh. So double in weight. The cost in cactus juice has been $64.50 so half a bottle. This is for a full blank, so it would be cheaper if a finished gear could be successful treated.
The process of soaking and baking has caused some problems but now i have a fully cured blank, we will see how it machines up and how it will affect the running of the clock. Next i will drum sand down to 16mm and then onto the CNC. So far this process seems to work like i had anticipated.

Pic 1 before baking the blank is screwed onto a faceplate.

Pic 2. Notice how dark the blank looks


Pic 3 the finished blank with some obvious imperfections.


Dean