From: lhawkins@olaf.wellesley.edu (Lee Hawkins)
Subject: Re: Aluminizing Service for Big Mirrors?
Keywords: aluminizing
Organization: Wellesley College
Date: Wed, 18 Nov 1992 04:04:28 GMT

In article <roelle.722037387@uars_mag> roelle@uars_mag.jhuapl.edu (Curtis Roelle) writes:
>Our local astronomy club (Westminster, MD) has a 24.6" Perkin-Elmer
>mirror requiring realuminizing.  Although we have obtained several
>estimates, some companies cannot accomodate mirrors of this aperture.

We had the same trouble here with our Perkin-Elmer 24.6"

>
>I am asking for names, addresses and telephone numbers of firms who
>can do a quality job.  Ballpark pices are also helpful, for
>both regular and enhanced coatings.

Price about $500
>
>Although we are willing to look nationwide, due to the fact
>that the mirror is full thickness, and when crated would weigh
>on the order of some 200 pounds, it would probably be delivered and
>retrieved by courier.  This imparts an east coast geographical bias,
>unless there is a significant price break farther away.

Place:

	Denton Vacuum
	2 Pin Oak Lane
	Cherry Hill Industrial Park
	Cherry Hill, NJ 08003

	Ph. 609-424-1012 and speak with Bill McConnell.

These folks know what they are doing, do a good job, and include a test of
the coating at no extra charge.  They also understand telescope mirrors
(you'd be surprised how many coating shops asked me "that's a
Ritchey-what mirror?").

Now for some advice and cautions:

	1) Insure your mirror for big $$$.  If it is a fused quartz
hyperboloid like ours, it will cost more than a few K to replace it.
Most carriers won't insure for this much (say $20,000), so you'll have
to take out third-party insurance.  If the mirror is only Pyrex, on the
other had, the max carrier insurance should cover it.

	2) Expect to pay almost as much or maybe even more for shipping
and insurance than coating, especially in light of 3)

	3) Minimize the time you mirror sets around on docks and trucks
by shipping Fed-X heavy freight or equivalent (but see 5 for why this
didn't quite work for us...).  DON'T ship via someone
like CF or Roadway.  They are good companies, but they're not quite as
careful as Fed-X.  Imagine your mirror as being on the bottom of a load
with a few thousand pounds of stuff sitting on it.  The problem should
be obvious.  

	4) Pack your mirror as if you expected it to be dropped twice
from  10' high and stand some chance of surviving.
	
	5) What ever you do, DO NOT ship a mirror this large to GM
Vacuum in California.  This is where we shipped our mirror originally,
and I got a call one morning from the guy saying:
	"Got you mirror on our rig, but it's too heavy for us to risk
coating, where should we send it."  So our mirror took a magical mystery
tour across country and back for no reason. Sheeesh.
>
>Curt Roelle
>roelle@sigi.jhuapl.edu

Good luck, 
Cheers,
--Lee
________________________________________________________________________________
R. Lee Hawkins					 lhawkins@annie.wellesley.edu
Department of Astronomy				 lhawkins@lucy.wellesley.edu
Whitin Observatory
Wellesley College                                   Ph. 617-283-2708
Wellesley, MA 02181                                 FAX 617-283-3642
________________________________________________________________________________