duofold - uk model size issue ?

[geoff-bristol]

I have a duofold Uk type from a late Uncle I have been servicing with a view to getting it to ink properly.

Its a barrel fill - not a button  - but I have an issue with its size - as it does not fit specs I have looked at ?

Capped length ( LCp ) is 123mm - but barrel max ( DBa) is 12.36mm ( 11.6 at thread - DTh )

 

Nib is marked N - 14 ct. which imjplies an early aeromatic ( from 53 )?

In the  Pendata European references it does mention a 'Demi' duofold from 1953- 58 - as well as a 'junior' model.

I cannot find sizes for those models ?

It would seem to have the barrel size of a Maxima - but the length of a slimfold  - according to a pdf of duofold specs.

 

The sac appears to be a numbr 17 - its reasonable condition but a new one would not go amiss ?

I stripped it no problems. I had tried filling and using it but it would not feed ink properly.

 

One issue is the breather tube seems a little short ? - out of the nib unit its approx 27mm -

is that right or should it be longer ?

 

I can post pics - but at present its in bits and it does not show much on the size issue.

 

I would like a spec on nib tip to shoulder of the section when fitted.

I have 1/8th max nib tip to black insert - and 3/4" tip to section ?

 

Any help - thanks - Geoff

 

[dipper]

You are probably correct to think the pen could be a "Demi".

I have also been gathering together info. about UK Duofolds and found gaps regarding the "Demi".

 

Here are some data points for you to check against your pen. (I am cross-referencing various sources on the wwweb here, not historical primary-sources.)

 

1953. Vacumatic UK Duofold "New Style" (NS) button filler discontinued. Replaced by UK "New Duofold" with Aerometric filler. (Note spelling "....metric" not "....matic".)

 

Two sizes at launch. Standard and Demi. The Demi is "shorter".

So I infer Standard and Demi are same diameter, but have not found that explicitly stated.

 

Primary source information. My 1958 "Standard" UK Duofold measures:

Total length capped = 129.7mm,

Body diam. just behind cap threads = 11.6mm,

Body diam. at widest = 12.5mm.

That is near identical in diameters to your pen, but shorter by 6.7mm, as described for a "Demi".

 

Other sizes were introduced or discontinued through the 1950's and early 1960's. It gets confusing! One thing that helps sort out the seven (?!) pen sizes is the nib engravings. (Nib sizes are 4, 5, 10, 15, 25, 35, 50.)

The wwweb says that the "Demi" nibs were engraved with the number 15, followed by a space, and then a digit indicating the year of manufacture.

My 1958 "Standard" nib is marked 25 8.

A 1953 "Demi" nib would be marked 15 3.

 

Something not mentioned in any wwweb sources, but visible in many photographs if you look closely, is that as the pen and nib sizes change then the number of side slits cut into the feed also changes. On my jobs-to-do-list is to trawl photographs and try to count the things. My "Standard", with its size 25 nib, has nine slits along each side of the feed, exposed under the nib.

How many slits in a Demi? Unknown, but if you count eight slits that would support the Demi hypothesis.

 

The "N" on your nib denotes Newhaven, a town on the UK south coast near to Brighton, location of the UK Parker factory. I have little information on which pens do or don't have an N on the nib engraving. I see some older pens that do (including the 1946-1952/3 Vacumatic button filler UK Duofolds), and many 1950's Aerometric UK Duofolds do not have the N. Still gathering data on that. My 1958 does not have an N. Just PARKER 14K ENGLAND 25 8.

So, just an idea to float ..... if your pen was made in 1953, the first year of the changeover from Vacumatic to Aerometric, it may have been built with a nib already engraved "N" as the Vac nibs, using up factory stock.

 

 

 

[geoff-bristol]

Thanks -

yes there seem to be quite a few variations on Uk after 1953 - reading more stuff.

I have sussed the breather tubes are only 25 - 30mm long - so thats ok.

 

One issue is the filler lever arm has parted company with the sleeve barrel - i think it should be spot welded ?

Not a huge problem as it works as it is.

The info I have gleaned so far has enabled me to refurb my old Parker 45 stainless barrel.

I have had it apart but never right down to the nib and collar/feed etc. After a thorough clean and the nib slit tweaked with shim

its writing very nicely.

It is however somewhat damaged ! - as about a year ago I tried cleaning it and soaked it in ethanol -

it did not like it ! The section plastic went somewhat rubbery - and reset itself hard but somewhat distorted.

This left the nib threads very tight - and the section fit to the filler tube/ink cartridge tight as well.

So I will treat it to a new/used section - we learn ! - but it suprised me that plastic would react to ethyl 98%.

 

I will check the feed slots - and let you know.

I have a few ebay bids on - testing out the prices on some of the older, button Duofolds - seem a healthy market.

 

 

 

[dipper]

On 3/18/2022 at 1:03 AM, geoff-bristol said:

it suprised me that plastic would react to ethyl 98%.

 

This page reports that UK Duofold pens bodies are polystyrene....

https://parkerpens.org/ukduofold.html

 

Perhaps a quick wash in acetone? .... 🤣🤣.

[effandpee]

That does sound like a demi model - it’s the same length as the Slimfold, but as chunky as the larger models. These pens do have a barrel imprint with the name, although it’s often very faint.

 

If helpful, the set of models that fall under this series are listed below (following the pens in the photo from L to R), with my attempt to record dimensions:

 

Lady (nib size 4) - 115mm (capped), 104mm  (uncapped)

Slimfold (5) - 125mm, 113mm

Junior (10) - 133mm, 121mm

Demi (15) - 125mm, 115mm

Duofold (25) - 130mm, 119mm

Senior (35) - 141mm, 129mm

Maxima (50) - 143mm, 133mm

[theredfalcon]

Hi all-further to above-added a few photos if it helps.

• First two show a demi sized nib against a Parker nib gauge. Nib tip to feed is about 2mm & nib tip to top of section is about 17mm

 

 

• Next one shows the date codes on some early pens- on the left is a standard size (black) with a 1952 Q1 date code & on the right is the same demi (red) with a 1951 date code -1951 codes tend to look like a square bracket ] . Parker Newhaven seems to have started date coding the Duofold/Victory pens & pencils in 1951. They also seem to have used the same tools for the barrel imprints on early Aerometric pens as on the AF versions so you get barrels for Demi/Duofold/Senior all with the same "Parker Duofold/REG TM/Made in England" inscription. These pens have also got the same barrel diameter-just different barrel lengths-Demi about 80mm, Standard only slightly longer at about 83mm & Senior about 92mm. 

 

• Next two show nibs/feeds. On left is a 1958 Duofold -9 slots in feed & nib marked Parker/14K/England/25 8 . Middle & right are the earlier pens from above-red Demi & black standard-both feeds have 12 slots each side & nibs marked Parker/Duofold/14K/Pen/N but Demi has narrower feed & smaller hole in section to take feed.

 

• 

 

With regards to the nib imprints, they seem to be marked with the "N" until about 1952, then from 1953-1959 they have the new Parker/14K/England imprint followed by the nib size. (Early 1953 nibs seem to be without a nib size). Some years have a single digit date code after the nib size as on the 1958 Duofold above while in other years the date code is on the bottom of the nib where it is hidden inside the section.