Burgundy pitch (Gugolz)

[rochler]

Howdoo folks!

Anybody here know where I can source some burgundy pitch for making laps? I've tried googling but nothing local comes up, but there must be some suppliers in AUS surely?

Any help greatly appreciated...:D

[cristian abarca]

Hi rochler my local ATM club source all their burgundy pitch from overseas. You could try http://www.telescopes-astronomy.com.au/telescopes036.htm and see if they have some.

regards Cristian

[fringe_dweller]

I dunno these guys?

http://www.shell-lap.com.au/

[rochler]

O.k. thanx I'll try them - but they don't list anything on their site (doesn't always mean much though!) At least they might know where I can get some.

Cheers! :)

[rochler]

Yep, they got some I think - I'll contact them. I think they only stock some local stuff though, not Gugolz.

I'll probably be contacting u 4 some advice on figuring when I get that far hehe.... but I won't be grinding for a while yet, I'm still getting organised.:D

[Satchmo]

Gugolz is black petroleum based pitch ( at least the stuff I use). I have tried Burgundy pitch years ago, it is clear coloured tree sap looking and didn't have nice properties at all that I remember. I bought a heap of burgundy pitch from Willmann Bell..its not on their web page but I'm sure they still sell it.

[Geoff45]

Here is an OS site that sells a lot of ATM stuff http://www.newportglass.com/angwcat.htm
Geoff

[rochler]

I've checked out the local options & Shelley's in Adelaide do not stock any type of pitch or resin laps. But www.telescopes-astronomy.com do stock something similar called 'Tropical Lap Resin' which Matthew advises is quite good & was used extensively by Uni of NSW.

After some searching on overseas sites it looks like Got Grit is a supplier of Gugolz - if you can afford shipping it here from Florida (!) Apparently they'll ship a kilo for $20 US + $7 shipping which seems very reasonable if true - their postage calculator might be on drugs though hehe....

Thanks for all your help folks, at least I now know what my options are!

Hope this is of use to some other folks too... :D

[Satchmo]

Just make sure the 'tropical lap' kit from SA has all the right ingredients included : gum rosin, wood flour and castor oil. This mixture was developed by Dr Con Tenukest at Uni of NSW in the 1960's due to the unavailability of polishing pitch in Australia. He passed away in the late 1980's and I purchased his 24" capacity polishing machine for $100 . Though it's now heavily modified , I use it every day in my optical workshop.

[rochler]

Yep, that sounds like the stuff alright - Matthew Lovell from www.telescopes-astronomy.com.au here in Adelaide distributes it & it has the same ingredients. Have you used this stuff before & how does it compare with pitch?

Wow, sounds like you got a real bargain with the grinding machine - bet that was many years ago though!

Cheers 'n thanx again...:)

[Satchmo]

Rochler : Be prepared to add more oil as needed . Rosin by its nature is very hard, harder than the hardest pitch. If your lap is too hard you won't be able to parabolise properly.

I bought the machine in 1988, but being home built and very heavy I don't think it was worth much more than that anyway.

[rochler]

Ta for the heads up on the hardness - I'll watch out for that. I might make myself a tester I think....

Cheers, Fred...

[cristian abarca]

Hi rochler. One way to test the hardness of pitch is to stick your fingernail on it and if after a few seconds you make an imprint on it then it's not too hard. You wont be able to stick you fingernail right in but you will just be able to leave a mark. If the pitch is too soft you may end up with a turned down edge, specially if you are not experienced. The first mirror I made ended up with a turned down edge during figuring because the pitch was too soft for my skill level. For what it's worth I know that Mathew uses that pitch to polish and figure his own mirrors, but it doesn't hurt to check.

regards Cristian

[Rod]

Hi Rochler,

I haven't posted before but thought I would add that I purchased gugolz pitch from gotgrit.com. It costs$10.00 US per pond. The url is:

http://gotgrit.com/index.php/cPath/2_8

Hope that helps.

Rod Brackenridge.

[DobDobDob]

Welcome Rod :welcome:

[garymck]

If you can't find any, I have some gugolz you can have a lend of (can't remeber what temper it was though) - I'd want it back when you've finished though!!

What size mirror do you have?

Returning a favor another ice in space member did for me......."passing it forward"

cheers
gary

[Blue Skies]

Try Mostyn Optical in QLD. I once tracked down the manufacturer in Germany and found out Mostyn were the agents for Australia, but they didn't know anything about the pitch. Anyway, I did get a shipment through them but it's all gone now except for one precious kilo I'm keeping for myself! (And getting it through customs was a little bit of fun, so glad I had a customs agent at the time, even though he was alarmed by it as well. "pitch" screams "highly flammable substance!!!" to those not in the know, and that is not supposed to be on a plane.) The last time I discussed getting more with a friend he said that he had contacted Mostyn Optical and they would take small orders, but that was some years ago, so the situation might have changed.

Otherwise get it from the USA. Other people I know have done that with no trouble.

[rochler]

Thanx Blue Skies, garymck. tailwag, rod & Cristian!

Sorry for delay in getting back, I've been tied up with other things - I've now sorted out an order with Got Grit in USA who are shipping me a batch of 1.5 kilo which should get me started.

It would be useful to have a supplier here in AUS so there isn't a big freight cost (it's around $25 US to ship 1.5 kilo i.e. 4.25 pounds packed weight which is a bit rich). A supplier would most probably be able to get better freight rate & larger quantities so I'll check out the Mostyn Optical in QLD to see what they say?

But if anybody is desperate to pay lots of freight it is certainly available from Got Grit (thanx Rod!)

Thanx also to garymck for your kind offer! I've only got a 6" mirror to grind but I've already ordered some pitch of my own, but appreciate your kindness. You're better off hanging on to it if you still intend to do any more mirrors hehe...

Anyhow, much appreciate you kind folks responding & helping me out!

Cheers & clear skies :D:D:D