A.M Compass Paint

Still around!  If you PM me with a conventional email address I can send compass manuals by free file transfer app “We Transfer”.

https://www.key.aero/comment/998680#comment-998680

Trying to get a message to TerryP, if he is still around.  I am trying to refurbish an old compass that looks like a P8 or P11….not sure.

I’d like to get hold of a parts list, overhaul instructions, etc to try to bring this back to life….it is not in great shape, but most of it is there…..

Thanks in advance,

Mark

P12 Overhaul Manual

Hi there,

Hope this works, if not PM me your contact details and I can e-mail the manual for you or the link should take you to Scribd.

KCA1501 P12 Compass Overhaul Manual

Hope that helps

Regards

Dave

Hi Terry. I realise this is an old post, but could I possibly get a copy of the overhaul instructions for the P 12 compass? I have recently refurbished our family Auster 5c and would like to have the compass overhauled as well.

Thanks,
Andrew

—————————————–
Hi Andrew,
Terry P. cannot answer you (or anyone ) at this time as his computer has blown up and is completely “clapped”. I’ve phoned Terry and told him about your post and he said OK, he’ll be in touch when he can get on Internet again, (No date known yet). I only live 7 miles away, so will relay anything during this period. Don’t think his mind is on A/C at this time, as his house heating Combi-boiler-Unit has also decided to expire, 😡 And as its still effectively winter time here, all their time is expended in keeping warm.

Hope this helps a bit,

Bill T.

Hi Terry. I realise this is an old post, but could I possibly get a copy of the overhaul instructions for the P 12 compass? I have recently refurbished our family Auster 5c and would like to have the compass overhauled as well.

Thanks,
Andrew

Terry, thank you for sending me the information. Edgar, great advice – thanks.

I also have a P11 that must have had mineral spirits in it. The paint was coming off the inside in large pieces. I may put the P11 bezel on the P8.

Dave

Pandect Instruments, of High Wycombe, can do them, as well.
The recommended liquid is alcohol, or I.M.S. 99, which must be totally de-aerated for at least 1 hour. The seal, under the glass, is (now) 3mm rubber (used to be 1/8″, or, sometimes, a gooey 2-part mixture,) and the seal, for the filler point, is a fibre washer, which must be placed in some of the alcohol, during the de-aeration process, so that no air pockets remain in the fibre. During the filling process, also, the flexible diaphragm, in the base of the inner bowl, must be pulled out, about 1/4″, to allow for any expansion/contraction of the fluid, due to temperature changes. The paint is a special alcohol-proof type, which is not proof against many other liquids, especially cellulose, or white spirit (used in many smaller compasses.) SIRS build these compasses, from new, and stock all known spares, since they took over the line from Smiths, along with the E2B/C & 6B/6C landing compasses.
Edgar

Excellent! Thanks for your help Terry!:D

I would reccomend Bruce Irvine at Airtron Instruments to get instruments checked and overhauled
e-mail [email]bruceirvine@tiscali.co.uk[/email]

Ken

PM sent Terry…:)

I have a parts list for the P11 compass (8 pages) including exploded view, and also for the “inverted type” the P12 (9 pages). I do also have overhaul instructions for the P12 (27 pages). Scanned at about 200 KB per page. PM me with your e-mail address if you’d like them.

I’m rebuilding a nice P8 compass for my chipmunk. It’s in decent shape but no fluid. It looks like the bottom seals are okay. It had some old dried up caulk around the glass so my guess is the fluid evaporated over time. If you or anyone else can email the parts list, exploded view and overhaul manual, please send me a PM.

Thanks

Dave

Thanks for the assistance Terry:)

Alcohol substitutes

For flight use, fuels are often not really the clarity required and would not be certifiable. Also consider fumes, toxicity, and fire risk. A Tiger’s ceiling and that of many veteran/vintage aircraft, may mean that de-aeration is not so important in practice but again there is certification to consider.

For static use almost any clear spirit should be OK. Yes, I’ve suggested vodka before, too. Or Gin maybe, and though not drinkable, surgical spirit from the chemist may be acceptable.

I filled one with Vodka…

Ah, now we’re talking!
I may do that with mine. Might fit a little tap on the side too…………..

Don’t mind me, just thinking aloud! 😀

You can buy compass fluid from LAS.

I filled one with Vodka (static only). Seemed to work OK!

Bruce

[QUOTE=TerryP;1357556]It is/was pure absolute ethyl alcohol de-natured with 5% pure methanol. When the bowl is filled it is de-aerated by holding it at 28 In of vacuum for one and a half hours. Then topped up again.
QUOTE]

How close to metholaded spirits is that, around my neck of the woods here in Southern Queensland, Australia we use avtur to refill P8/P11 when we overhaul them. I have been using one in my Tiger for about 25 years with little downside.

Having said that, I am thinking of replacing it with a recently O/H unit because the liquit is a bit yellow now and with ski googles on (yellow filter) it is getting a bit harder to read (or is my eyesight going with age).

cheers

Cheers Bruce, i’ve sent them a message regarding a couple of P12’s….. Sounds expensive.

SIRS Navigation

Thanks again for the tips, do you know anyone that can service these compasses?

Thanks,

Tim.

Alcohol

It is/was pure absolute ethyl alcohol de-natured with 5% pure methanol. When the bowl is filled it is de-aerated by holding it at 28 In of vacuum for one and a half hours. Then topped up again.

Radiation:
Please note that compasses pre mod B/279 present a “minor” radiation hazard. Post mod they still contain slight raduioactivity. Removal of luminous paint should not be attempted.