Seiko SRPD55 Mod

This Seiko SRPD55 Mod was put together for a client here in Cornwall. The original idea was to mix the Seiko SRPD79 dial, hour and minute hands with a red submariner second hand. Also, chapter ring modded to include red hour markers and put this into the stainless steel case. (See this mock up below.)

Although these images are pretty “raw”, they are great to help the client visualise what they want. An assistance if I haven’t got any photos or the request is a little out of the norm.

We started with the Seiko SRPD55, with the idea of a black Yacht Master. So, this Seiko Mod includes; a brushed stainless steel chapter ring, the double dome blue AR coated crystal and finished with a black Yacht Master bezel.

Seiko SRPD55 Diving watch - Before modification displayed with its original white Seiko box, instructions, bracelet and the modification parts including Black Steel Yacht Master bezel insert, double dome sapphire crystal and stainless steel chapter ring.

Seiko SRPD55 Mod – Bezel Insert

The bezel is removed from the watch, which allows the insert to be separated from the bezel.

Seiko modification Process - Seiko SRPD55 Diver watch. Stainless Steel with black dial, displayed on a watchmakers cushion with the bezel and insert separated (parted) and the bezel click spring along. side. The watch sits centre front. Seiko Bezel stip down, insert replacement.

The insert is attached to the bezel with double sided tape. This needs to be removed before the new bezel insert can be put in place with some fresh tape. Acetone and a little plastic scraper makes light work of this and prepares the bezel – removing the grease so the new sticky tape gains a good adhesion to the steel.

Seiko Mod Prosess - Seiko SRPD55 polished stainless steel bezel after the original bezel insert has been removed, there is still glue left behind from the original double sided tape. next to the bezel is a plastic tool that is used to remove the redundant adhesive without scratching the bezel.

Removal of the Crystal & Chapter Ring

The case back, crown, movement and dial need to be removed to install the stainless steel chapter ring and double dome sapphire crystal. (This blog was so long in the making because I tend to forget to photograph each stage of the process!)

Seiko Mod Process - SRPD55 Stainless steel Case with bezel, caseback, crown, movement, dial, hands removed. The Seiko watch case is complete with the original crystal and chapter ring. The case is displayed on a watchmakers cushion. surrounded by the new modification parts Black steel Yacht Master bezel insert (right), stainless steel chapter ring without markings and sapphire double dome crystal left. Below are the original bezel spring, Bezel and exhibition caseback along with the original watch tag.

The crystal comes away using a press with a satisfying pop! The gasket and chapter ring come with it, but mostly these need to be removed separately.

Seiko sapphire crystal replacement - Seiko modding process, removal of the original flat Seiko crystal using a press. The stainless steel watch case is face down on a die which is taped with low tack tape to protect the watch case, while the crystal is removed with a further taped up die from the top. Seiko SRPD, SKX.

Installation of the new Sapphire Crystal & Chapter Ring

The new chapter ring can be dropped into place. Sometimes these can be a little loose fitting. The after market producers of these recommend you use a little glue to hold them in place. This one was a perfect fit, the positioning key being a snug fit also!

Seiko Mod Process - The original Seiko SRPD bare case displayed on watchmakers cushion with the new stainless steel chapter ring installed.

The gasket is placed on top of the chapter ring with a touch of silicone grease to help with water resistance. This also helps to reduce the friction, allowing the crystal to slide right in.

Seiko Mod Process - Seiko SRPD Mod. The case is displayed on a watchmakers cushion, with the new double dome sapphire crystal fitted and stainless steel chapter ring. Other than this the watch case is bare.

Water Resistance Test

The watch is then pressure tested to check the modifications have not affected the water resistance.

After a successful test, the case is put to dry. Whilst this takes place, the bezel tape can be applied ready for the assembly of the watch. If you would like full details on modifying a Seiko 5KX (SRPD55) or other see here.