Restoration project Spencer Jug Handle Model No. 36H

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Tom Graham
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Restoration project Spencer Jug Handle Model No. 36H

#1 Post by Tom Graham » Sun Dec 25, 2022 2:12 pm

I’m going to practice with my ShopGoodwill.com find and try to restore the Spencer Model No. 36H that I’ve recently purchased and posted in a recent thread. It was a little rougher than it initially appeared and I’m not convinced that all of the black paint was original. Others might object that I didn’t choose to leave it as all original, but I have already had great fun learning how it was assembled.

I now have it almost completely dissembled; but I can use some help with the fine focuser.

Does anyone know how to disassemble the fine focuser from the jug handle? Those are the very last bits that I lack before a good soaking of all the painted parts.

…And any words of warning are appreciated…

Question: Does anyone know for sure whether the fine focuser large and/or small knurled focuser knobs (and the pin-holed collar nut are designed to unscrew at this point of disassembly?


I have had the entire assembly soaking in penetrating oil for multiple days — to no avail.

I would not be surprised to find that I will need to use a lot of force, but I definitely need to know whether they have standard, right handed threads before applying more force. (Earlier, I was surprised to learn that you rotate the fine focus knob all the way clockwise (?!) (when viewed from the top) to expose two spanner pin holes.)

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apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#2 Post by apochronaut » Mon Dec 26, 2022 12:21 am

Spencer had 4 fine focusing systems around the first w.w. The system on yours is called Fine Adjustment C. It works similarly to the patent you picture but the geometry is different due to the obvious obstacle of the jug handle. The pressure is transferred to the optical tube via a teeter totter arm on a fulcrum bearing. The knurled knob when turned counter clockwise on it's left hand micrometer thread drives a shaft with a needle bearing end down against the proximal end of the teeter totter causing the other end to lift the optical tube.

Being able to unthread the knob to expose the fixed nut is normal. It happens when you reach the end of travel in the down position. In fact you can thread the shaft right out of the nut. Removing that nut will expose the innards at the fore end of the seesaw. I have never had reason to remove that nut but I can see no reason why it would not be right hand thread.

A single fine focusing control was common in the early days of microscope design and the central arm version became a standard design. As models became more sophisticated and the left/right knobs on a horizontal shaft for the fine focus dominated designs, companies struggled with balancing ergonomic designs with traditional designs and conservative customer requirements. In 1920's catalogues, Spencer makes it very clear that they have designed a couple of models in order to appeal to older microscopists who are used to certain design features ; a principal one being the single knob vertical shaft fine focus. This was the Fine Adjustment A.
In 1930, their flagship research stand the Spencer # 7 had a 1 micrometer dual knob horizontal shaft fine focus, known as Fine Adjustment D but they still offered an identical microscope the Spencer #14 ; identical in all ways except it retained the single knob central arm Fine Adjustment A, still popular with older biological resesrchers.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#3 Post by Tom Graham » Mon Dec 26, 2022 1:17 am

Thank you! This is very helpful. I can see the aft end of the lever and realized the relatively shallow mechanism that you’ve described (given the space constraint caused by the finger holes of the jug handle.) And I’ve collected the pin; though I was uncertain where it would go back in.

So, continue to turn the knurled fine adjustment knob counter-clockwise, even after it has bottomed in its downward motion on its left-handed thread — and ultimately removing the knurled fine adjustment knob using a counter-clockwise rotation? Correct?

From what I’ve tried so far, this will take a tremendous amount of force. I will likely need to find the smallest strap wrench to apply more leverage to it than I already have.

By the way, my primary reason for dissembling this piece is to strip, clean and refinish the black components —without risking damage to the finish on the silver bits.


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apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#4 Post by apochronaut » Mon Dec 26, 2022 2:50 am

Tom Graham wrote:
Mon Dec 26, 2022 1:17 am
Thank you! This is very helpful. I can see the aft end of the lever and realized the relatively shallow mechanism that you’ve described (given the space constraint caused by the finger holes of the jug handle.) And I’ve collected the pin; though I was uncertain where it would go back in.

So, continue to turn the knurled fine adjustment knob counter-clockwise, even after it has bottomed in its downward motion on its left-handed thread — and ultimately removing the knurled fine adjustment knob using a counter-clockwise rotation? Correct?

From what I’ve tried so far, this will take a tremendous amount of force. I will likely need to find the smallest strap wrench to apply more leverage to it than I already have.

By the way, my primary reason for dissembling this piece is to strip, clean and refinish the black components —without risking damage to the finish on the silver bits.


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That would be clockwise to unscrew a left handed thread. In my description I mentioned that counter clockwise drives it down and thus tightens it. Turn it clockwise and it should just thread out.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#5 Post by Tom Graham » Mon Dec 26, 2022 3:47 am

apochronaut wrote:
Mon Dec 26, 2022 2:50 am
That would be clockwise to unscrew a left handed thread. In my description I mentioned that counter clockwise drives it down and thus tightens it. Turn it clockwise and it should just thread out.
I stand corrected. And thank you.
Clockwise to remove a left-handed thread as in the case of fine adjustment knurled knob.

Whereas the threads on the rounded, pin-hold lock nut underneath is a standard, right-handed thread.

Once I removed both, I found that there is a brass spanner type lock nut designed to create a travel limitation on the threaded shaft of the knurled thumbscrew.

I now believe that the entire assembly is designed to be removed in one piece by extracting what I’ve called the pin-holed locknut. (Rather than removing the fine adjustment knob first —which will pull the brass lock nut into a bind.

A big thank you to @apochranaut for the insight and correction and encouragement.

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apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#6 Post by apochronaut » Mon Dec 26, 2022 4:14 am

I am still intrigued by the parts being what appears to be chrome on brass. Chroming wasn't really done until the 20's. You might consider that your instrument is newer than your edtimate. The mechanical stage is also a more recent design...late 20's maybe. I have never seen chrome on any of them before the 20's. Nickel yes, not chrome.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#7 Post by Tom Graham » Mon Dec 26, 2022 1:42 pm

apochronaut wrote:
Mon Dec 26, 2022 4:14 am
I am still intrigued by the parts being what appears to be chrome on brass. Chroming wasn't really done until the 20's. You might consider that your instrument is newer than your edtimate. The mechanical stage is also a more recent design...late 20's maybe. I have never seen chrome on any of them before the 20's. Nickel yes, not chrome.
I’ve not yet learned how to distinguish between plating materials such as chrome, silver (or palladium). In my lifetime, only chrome had been commonly used. If I’ve said silver or chrome, it’s only intended to be an inexact reference to color — and not definitive regarding plating material.

I welcome anything you’d like to share in that regard.

My only estimate of the age is based purely on the serial number ( serial 19898) on the base*. If other photos or information can help you in any way, please let me know.

If the tiny slotted set screw holding the lever of the fine adjustment mechanism in place is easily removed, I’ll do that next. Otherwise, I will likely begin to soak and strip the non-silver bits today.

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*From Herbert Gold’s chart:
Serial Number. Approx. Date of Shipment
10,000 About Jun. 1909
20,000 Apr. 27, 1913

On P.S. Neeley’s website: https://user.xmission.com/~psneeley/Per ... Window.pdf

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#8 Post by Tom Graham » Mon Dec 26, 2022 2:43 pm

And now with the very small (and initially, paint covered) set screw to the lever removed, the entire fine adjustment mechanism “A” is disassembled. Interestingly the original lubricant could be found at the top of the spring and it was a green color.

Can you see the stamped numbers 43 and 48 in the second image? I assume those are part numbers.

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BramHuntingNematodes
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Re: Restoration project Spencer Jug Handle Model No. 36H

#9 Post by BramHuntingNematodes » Mon Dec 26, 2022 3:42 pm

All the old grease I see has a green rime I would assume from the copper in the brass
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#10 Post by apochronaut » Mon Dec 26, 2022 5:12 pm

It all looks promising.

Green microscope lubricants found in old microscopes are caused by the action of sulphur on copper in the brass, from the whale oil base that was used for them. Most of the lubricants were whale oil based since it was unparalleled as a stable and versatile lubricant. It is no accident that Nye lubricants are located in coastal Maine.

There are a few scenarios that I can think of that would account for a 1913 serial # on your microscope, yet a group of fittings that date from the early 1930's. Chrome was definitely not a possibility in 1913 and nickel would be oxidized. The design of those objective barrels and slide control knobs did not arrive until at least 1929, the earliest catalogue I can find that depicts the slide control knobs, you have. Earlier ones were shaped like a half torus and either brass or enamelled black.
Although the objectives appear to be the later incarnation of the front lenscap style used from about 1918 to 1930, having chrome plating with a distinctive black band denoting the 95X, they could be replacements. Objectives fitted in 1913 would have been brass of a different barrel design, with only 5 digit serial #'s and likely would not have a magnification on them. 16mm either NAp .25 or .30 , 4mm NAp. .70,.75 or .85 and 1.8mm or 1.5mm NAp. 1.25 or 1.30 were the common ones.
My guess is your objectives are marked 10X .25, 16mm, 44X .66 4mm and 95X 1.25 1.8mm. A six digit serial # on each.

As models were dropped from the catalogue, a remaining parts inventory would still allow for the assembly of a custom order. The serial # would have been pre-stamped into the base casting left in inventory. I don't see the model 36 catalogued after 1917 but it possibly could still be ordered in the later 20's, fitted with contemporary fittings.

Someone returned a 1913 microscope 17 or so years later for a factory refurb. They might have replaced anything that was suspect.

Someone purchased new objectives and a new mechanical stage for a scope and decided to get the remaining brass parts chromed to match. Chroming had few environmental controls on it until into the 1980's. It was cheap and chroming shops abundant. Chroming on brass especially was cheap since preparation of the piece was easy and no interplate was necessary.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#11 Post by Tom Graham » Mon Dec 26, 2022 8:42 pm

Ironically, though unique, the use of chrome bits doesn’t appeal to me aesthetically nearly as much as would polished brass (or even the unique yellow lacquer.)

I wonder whether it’s possible to source these chrome pieces in the (more age appropriate) yellow lacquer?

At least a few parts are definitely yellow lacquer covered with black paint (such as the arm portion of the fine adjustment mechanism which I’ve just disassembled.) But the base is not. I’ve begun to strip it, and it is simply unfinished brass.

I wonder (as you’ve speculated) whether it is most might likely that this didn’t first sell until much later and the chrome was added at that time. Even the tiny pointer at the fine adjustment micrometer is chrome.


Here’s how the objectives are labeled:

16MM.N.A.0.25 10X 248031
4MM.N.A.0.66 44X 274824
1.8 MM.NA .125:95X::Hom.Imm. 315970

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Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#12 Post by Tom Graham » Mon Dec 26, 2022 9:27 pm

Wow! All I can say is, wow. Someone should have warned me how beautiful unfinished brass can be. Who needs paint?

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apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#13 Post by apochronaut » Mon Dec 26, 2022 10:32 pm

I think in a laboratory situation , the baked enamel proved to be more durable. Brass will tarnish easily and badly if not protected with lacquer and the lacquer wears off much more easily. Black also reduces glare from the remote lamp. Much microscopy would have been done in low light levels at night and I can attest that a black microscope reduces peripheral glare when at the eyepiece.
Your objectives and eyepieces date from around 1930 or a little later. I am not 100% sure when the tapered eyepieces came on the scene but it was after 1930.

Another possibility came to me. Perhaps there was some company anniversary in the early 30's snd they put together some vintage stands from overstock castings and contemporary chromed fittings. Even the inclnation nut is chromed.

edit. I found the tapered type eyepieces in the 1928 catalogue, and the objectives with the Sedge Hat style front lens housing would date from around then also. I have 1925 microscope that had the earlier flat topped eyepieces.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#14 Post by Tom Graham » Mon Dec 26, 2022 11:35 pm

Earlier you referred to the “slide control knobs”. Are you referring to the design of the iris diaphragm? Since we’re speculating, do the design of the diaphragm, of the mechanical stage or even the case, help to date it?

Finally, I’ll be open to any and all recommendations on refinishing it…knowing that black and chrome are how it arrived to me.

(And if this one should remain black and chrome,now that I’ve disassembled one, I’m not opposed to searching again later for one that was originally brass.)

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Re: Restoration project Spencer Jug Handle Model No. 36H

#15 Post by BramHuntingNematodes » Mon Dec 26, 2022 11:53 pm

If you like the brass then clear shellac is traditional. You can rub on the shellac or spray it then fume in alcohol.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#16 Post by apochronaut » Tue Dec 27, 2022 2:31 am

Tom Graham wrote:
Mon Dec 26, 2022 11:35 pm
Earlier you referred to the “slide control knobs”. Are you referring to the design of the iris diaphragm? Since we’re speculating, do the design of the diaphragm, of the mechanical stage or even the case, help to date it?

Finally, I’ll be open to any and all recommendations on refinishing it…knowing that black and chrome are how it arrived to me.

(And if this one should remain black and chrome,now that I’ve disassembled one, I’m not opposed to searching again later for one that was originally brass.)

Slide control knobs also known as stage controls, XY controls. 1928 looks to be about the earliest that those convex knobs such as you have were used.

That model of microscope used a swingout type of condenser with a threaded pillar type of Z adjustment. Spencer slowly discontinued that type over time and it became relegated to older and simpler models pitched primarily at scholastic and small lab markets. In 1917 all models had a swingout type, by 1924 all of the elite models had been fitted with dovetail type condensers on a rack and pinion and by 1930 , all microscopes had dovetail mounts with rack and pinion or in the case of simpler designs a helicoid adjustment or a fixed mount.

There might not have ever been a version of that microscope in brass. Even a version of it in 1913, would have been enamelled. There is some clown on ebay that buys scopes older than the 50's and strips them down to the brass and steel or iron. Then he puts $1000.00 on them and tries to hawk them as brass antiques. Most of them look ridiculous. It takes all the elegance out of their design, leaving them looking like a polished boat anchor or some patented potato masher from 1900 or something.
The brass wasn't originally there to look at. That has just become a kind of modern fixation with things old. Brass microscopes faded from view about the end of the Edwardian era, probably when reagent proof enamels became possible. Lacquered brass was originally used due to it's combination of weight and relatively good resistance to moisture and reagents ; when compared to iron and steel. Once good reagent proof paint came along, it proved a superior more practical surface, even though brass continued to be used in most bodies for it's weight. Some lesser instruments used lead filled cast iron bases or just cast iron.

I would use gloss black lacquer or enamel, just as the original was done. In some ways it is unfortunate that the flittings are more modern and have been chromed because black enamelled older microscopes with brass fittings are quite elegant indeed.

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Re: Restoration project Spencer Jug Handle Model No. 36H

#17 Post by BramHuntingNematodes » Tue Dec 27, 2022 7:17 am

I am doing a bit of reading on early twentieth century ripolin formulations and here I think some.anachronism is for the best. Blown oil and copal admixtures, diterpene resins and maybe some lead for good measure.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#18 Post by apochronaut » Tue Dec 27, 2022 8:39 am

Good thing that wasn't copious admixtures. In fact though, a copious admixture of turpentine was the key to the process of baking enamel. This was a varnish based enamel , as opposed to porcelain enamel or " fused enamel" otherwise known as Japaning., a glass based enamel
Baked enamel developed out of the auto industry where it was discovered that a water thin varnish based paint could be baked on, quickly evaporating the turpentine, leaving a hard, durable finish that obscured brush strokes during the baking process.

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#19 Post by Tom Graham » Tue Dec 27, 2022 1:57 pm

Some of the black paint is much tougher to strip than other.

After stripping and polishing three of the largest pieces (of the base and the arm), I’ve arrived at the inclination joint. After 4 separate soakings in KleanStrip stripper, that hasn’t even begun to soften the black paint on these three pieces. (And that’s after soaking half a day in Naptha.) I scrubbed on one small piece (that bolts to the understage) for 20 minutes in with Brasso and finally began to wear through part of the paint. Boy, that is well painted!

What paint color bast matches the original black? (I’m not equipped for any fuming, manual shellacs, resins, lead additives, admixtures, or adventures.)

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apochronaut
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Re: Restoration project Spencer Jug Handle Model No. 36H

#20 Post by apochronaut » Tue Dec 27, 2022 3:08 pm

Just use rattle can enamel, not lacquer. Valspar Tractor paint is good. Rust-Oleum, Dem-Kote. There is one called Dutch Boy that is supposed to be good. I heard Rembrandt used it from rattle cans. It's going to be a shelf princess anyway, isn't it?

Tom Graham
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Re: Restoration project Spencer Jug Handle Model No. 36H

#21 Post by Tom Graham » Tue Dec 27, 2022 4:25 pm

apochronaut wrote:
Tue Dec 27, 2022 3:08 pm
Just use rattle can enamel, not lacquer. Valspar Tractor paint is good. Rust-Oleum, Dem-Kote. There is one called Dutch Boy that is supposed to be good. I heard Rembrandt used it from rattle cans. It's going to be a shelf princess anyway, isn't it?
“Shelf princess.” I think that’s what I’ll call it.

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