Homemade pitch for polishing
Posted 27 March 2010 - 04:23 AM
I was searching for info how to make your own polishing pitch and stumbled on this : http://en.wikibooks....g#Lap_Materials
If I understand correctly you can use only rosin from conifer trees for your pitch
you can use only beeswax to make your pitch for polishing ( since I am beekeeper I have lots of pure natural wax )
Is rosin only or wax only pitch doable ?
Posted 27 March 2010 - 10:51 AM
My understanding is that pitch, bees wax, rosin and linseed oil are all components of tempered pitch such as that sold by many companies. Since the post from a few weeks ago concerning recycling pitch, I have been experimenting. I brought an old electric range that was in storage and set it up outside. I have in the past collected pinon resin from the pinon pine tree that is very abundant here. I have used it (also in the past) by dissolving it in acetone and letting it drain through a strainer cloth and boiling the acetone off, but that was very dangerous and time consuming. (done also outside away from every thing.) Last week I took a bunch of old pitch and even acculap and made a forces strainer from a #10 can and made pitch from it. It is still untried but looks good so far. It came out pretty close to the right hardness and could be easily adjusted. It is not as clear as the tempered pitch that I have bought. I ordered some rosin and refined bees wax from Willman Bell. (are we allowed to mention our sources here?). I will try different combinations and see how they work. This picture is the #10 can showing an air chuck attached to the top , sealed with rubber O rings. A two layer bed sheet filter and sieve will be attached to the bottom with the shown ring clamp. This is after the can is filled with the material to be filtered. The sieve should have ears for sitting on another container and the whole thing is sat on a steel bowl and heated in the oven for about an hour at 250F. Very gentle air pressure is then applied and the pitch runs out the bottom into the bowl.
Posted 27 March 2010 - 11:07 AM
Posted 27 March 2010 - 11:10 AM
Posted 27 March 2010 - 12:43 PM
So my plan is to go get some rosin from a tree and mix that with wax and see where it gets me hehe. I guess I will have to experiment but some "official" formula from you guys would be great.
I would trade right away hehe but we are thousands of miles apart
Posted 27 March 2010 - 01:43 PM
The 6" F8 mirror was also recommended to first time mirror makers for a good reason, the difference between a sphere and a parabola at this size and f ratio is very small. The normal, random grinding and polishing strokes will almost always produce a good sphere and by polishing with just a bit of extra overhang for just the right amount of time the 6" F8 sphere will be very close to a good parabolic figure (or so the teachers said). Many first time ATM's built their first mirror without any testing on faith using the described method. Sure the resulting mirrors were far from perfect, but they would work well enough to encourage the novice to try again and make a better mirror.
Posted 27 March 2010 - 01:54 PM
I am well into fine grinding 6" f6 now Originally the glass was grinded to f10 years ago and only needed polishing but I decided to go shorter
I have to come up with something in 2 days now haha Unfortunately even if wax works I don't have any foundation since I leave wax making to the bees
Posted 27 March 2010 - 04:28 PM
Am I overthinking everything and should I just order some acculap or gugolz and wait like a month for it to arrive
Posted 27 March 2010 - 05:03 PM
Posted 27 March 2010 - 05:10 PM
I am overseas and I do order from US on regular basis and it takes from 10 days to a month for a package to arrive.
The thing is that I think I got some sort of a "mirror bug" and will just go ahead with wax. Maybe mix a little resin there and will see what will happen
If anyone would like to add something please do. I am 2 days from polishing
Posted 27 March 2010 - 06:49 PM
Order the pitch now so by the time you give up on the wax you'll have it there.
Posted 27 March 2010 - 10:27 PM
Posted 30 March 2010 - 06:41 PM
I filtered it through cotton cloth and have it 50g. It is very "playable" and flows and flows and flows In this state it certainly is not suitable for polishing so I ask you guys what should I add to harden it a little ? Will cooking it a little help ?