stern removal

Time set position is for ETA 28xx series. On the 21j and most others you want to remove the stem in winding position. You will want to reinsert it while pressing the release button. (I'm a watchsmith) , with the ETA 2824 you should have the keyless works in time setting position when you remove the stem otherwise some of the component parts get out of sync and you have to reassemble them from the dial side.

Watch Hands Installation TUTORIAL -

 

On these movements you need to use the red screwdriver to push the stem release button, it's just the right size.

dial dot

 Dial dots are this sort of stuff, available with paper backing on both sides for handling and applying.

They do add some thickness, about 0.25 mm when finally compressed in the case, not enough to interfer with hand, unless the watch had abnormally tight clearances to start with.

The main concern is keeping the dot off anything that moves on the front side of the movement.

on ETA 2824 and 2836 you can just glue directly to the spacer ring and don't need the feet.

How to reattach fallen Dial Indices

Hangzhou 6311 Seagull ST2100

Seagull ST2100

My estimate is that these two movements, the Seagull and the Hangzhou are priced about the same. The additional work done on the Seagull to decorate the external features is compensated for by skipping minor non-essential work in unseen areas. While the Hangzhou maintains a uniform dull workmanlike finish everywhere.

Also, the Hangzhou is manufactured more like the ETA than the Seagull, every part and almost every machine cut is the same on the Hangzhou as on the ETA. It just has three more jewels (for a total of 28, same as the Seagull.)

The Seagull, however, is not "just a copy" of he ETA 2824-2. It is a re-engineered version of the ETA 2824-2. Unnecessary, wasteful and difficult processes have been removed and a more simplified process put in their place. This is another way Seagull can spend more time on making the outside pretty, without increasing the production time and thus controlling the cost.

Which one would I use in a watch, if I were to make one (on a mass scale)? The Seagull.

Now, you may ask why would I pick the one that I have just ranked the lowest for my choice. There are several reasons, not the least is the name "Seagull," which does carry some weight, in that it is known as a quality movement producer. The second reason is the Seagull just looks so much better that the poor plain Hangzhou. And third, there is no real performance reason not to. The Seagull is just as clean and nice where it matters as either the ETA or the Hangzhou.

General notes on the overall design of the 2824-2 - The 2824-2 is the end of a long and involved evolution of movements. The end requirement was, apparently to make the least expensive movement possible, while maintaining reliability. Just about all of the springs are integrated into the parts that need them, this makes the 2824-2 one of the easier movements to work on.

By using the design of the ETA 2824-2, the Chinese have copied one of the best (affordable) movements offered by the Swiss today. It is not a vintage Elgin, from say, 1950, (the pinnacle of movement making, in my opinion) or a Rolex 3135, but then these movements don't cost what an Elgin did in 1950, or what a 3135 does today.

Provided the watch manufacturer keeps fingers off the balance wheel and dust and debris from floating around the inside of the case, either of the two Chinese movements should provide an excellent engine for any watch.

Swap a 2824 into a 3135

 

2824 into a SH3135 case
ETA 2824-2 into a SA3135 case

2824 in a Submariner which had a 3135 movement installed 

proper movement holder , new dial , DWO a 2836 date disc will fit on a 2824 but not vice versa and new hands too , but its possible

H4 pinion. 

But most asian 2824 clone and ETA 2824-2 come with H2 pinions as standard. Therefore you might need to upgrade the H2 pinions to H4 if you are going to source an asian 2824-2 clone / ETA 2824-2 instead of a TC 2824-2. Pinion change requires disassembling the movement and that is tricky

2. The right movement ring is also needed, I have no idea which one would work for SA3135 cases but TC sells movement rings as well for his TC 2824-2 - those should definitely fit

3. Using a 2824-2 movement (whether it is TC, ETA or Asian clone) also requires you to install a datewheel overlay in order to correctly position the date beneath the dial's date window. You will also need to order that and install it if you are going to install a 2824-2 based movement - TC also sells high quality datewheel overlay

4. If you are going to fit a 2824-2 movement (whether it is TC, ETA or Asian clone) into your SA3135 case, please also note that the existing SA3135 dial have dial feet positions that are different to the 2824-2 movement. Therefore, you must cut the dial feet off the existing SA3135 dial and stick the dial onto the movement ring using sticky dial dot (I have also done that similarly by using a minimum amount double-sided sticky tape)

5. The stock SA3135 hand pinion sizes are different to 2824-2 / 2836-2 movements (whether it is TC, ETA or Asian clone). Therefore you will also need to buy the correct hands if you are going to use a 2824-2 movement as the existing SA3135 hands would not fit. You can try sourcing the Noob 116610 V7 / V6 / V5 etc A2836-2 hands from the TD as these will provide the correct lume colour and they are reported to be the highest quality for aftermarket clone hands. eBay sub hands from experience all suck, including WSO stuff.

Eta 2846 swap to 2836

Eta 2846 is a good direct replacement and its stem height is exactly the same as a 2836-2. you can switch out a 2836 with a 2846. Direct swap... The dial, hands and datewheel transfer over.

ETA 2846

Features
automatic
sweep second
day: quickset, 2 languages
date: quickset
option: no day

Data
11.5''', Dm= 25.6mm, Do= 26.0mm
H= 5.2mm
F= 1.65mm
T= 2.25mm
17/21 jewels
f = 21600 A/h
power reserve 48h

Balance staff ETA 2846

Stem W3738

Mainspring / battery
1.23 x 10.5 x 0.11 x 450mm

Hands
1.50 x 0.90 x 0.25mm