Swapping a MBK acrylic glass for a clark, any advice ?

[docdoc]

Hello,

Before I break everything in pieces do you have any advice how to swap the MBK regular acrylic glass of a 1665 with the clark I just received ?

Do I need to be gentle or be firm with my crystal press ?

Any adice is more than welcome

[Nanuq]

Heck I use a hockey puck to put mine back together so anything more gentle than that ought to be golden.

I use a tiny smear of silicon grease or even vaseline at the very bottom of the crystal, perhaps the bottom 1/8" or less, around the outside edge ... not the inside edge. Then when pressing the ring down, that lubricates the last smidgen to help it seat better and makes it less likely you'll crack the crystal. It also pushes a tiny bit of sealant between the case and the bottom lip of the crystal, to prevent corrosion from starting in that gap.

Press it down tight, and Robert's yer uncle. No worries.

[jmb]

Are you talking glass "glass" or plexi/acrylic crystal? The acrylic crystals are secured by a compression/retention ring that is pressed down over the crystal which "squeezes" it against the case. Make sure you don't tear up your original crystal as you may need it again. I tried a Clarks and a different T-19 crystal and found my compression ring slid easily over the Clarks crystal but I had to use a crystal press to fully seat the ring on the other one. I was afraid the Clarks would fall off, or at best leak. So much for standards and interchangeability. Someday I will machine a different ring that has a few thousandths small ID and install the Clarks...

[kbh]

Just curious! Don't you guys use any adhesive on the inside of the glass.

I used a small bead of GS hypo cement for added water tightness. It's at least passed the swimming pool test.

[jmb]

I used an O-ring (like on a case back) under the compression ring. The inside bottom of the ring was slightly radiused and I felt this would give room for the O-ring and also compress it against the crystal/case junction. I have not been brave enough to toss it in a bucket, yet! I wouldn't think a fine bead of RTV around the crystal base would be out of line...

[alligoat]

Just curious! Don't you guys use any adhesive on the inside of the glass.

I used a small bead of GS hypo cement for added water tightness. It's at least passed the swimming pool test.

I did the same thing on my CN 5513 which also has the compression ring- worked fine in the pool. But I would think an o-ring and some silicone grease would be better in terms of reversibility.

[docdoc]

well no I need to take the dive

The thing I am the more concern about is to keep the waterproof of the watch.

Edited January 27, 2010 by docdoc

[Nanuq]

If your crystal retaining ring is fairly hard to press down, and you use a tiny smear of silicon grease, that sucker will be plenty waterproof at the crystal for even shallow diving.

If, like JMB found, the crystal ring goes on too easily then your crystal thickness is wrong and it's not being squeezed on correctly. Likely this one will leak.

[docdoc]

Ok thanks for the plenty of advices

[offshore]

@docdoc,

If you decide to go the glue route, and you don't have a glue, think about using a UV cure glue like Loctite 358.

You will find it very easy to use(work with),it is very thin and "runny", dries hard in a few minutes in the sun, and cures in 24 hours. Acetone is a solvent to clean up if needed.

GS Hypo is also a good choice, although a little more difficult to work with, although that is in some ways made up for with the great little applicator on the tube.

O/S

[Nanuq]

Thanks for the great advice, Offshore. Another "insider" trick of the trade.

Is that stuff for sale over at WatchBitz?

[docdoc]

ok thanks

[offshore]

@Nanug,

We have the GS Hypo, and I am in the process of getting supplies of a range of Loctite products.

Maybe another month!

O/S

[docdoc]

THe operation went just fine. The hockey puck is a definetely a must try. It helps me to make the final touch thanks again to all of you.

And I test it with a 40 minutes swimming pool bath today and it keeps great waterproofing

[cib0rgman]

I think you need work the compression ring a little bit Clark's acrylic is a tiny bit thicker. I do not have Glue on my 1665. I have taken my watch to 100 feet dive and not problem at all. Mine has a 1570 inside.

cheers

[vortx]

any tip of how to get the retaining ring off? I smashed the original plexi (mbw) but still cant get the ring off... regretting it now, but am determined to fit the clarks crystal.

[Nanuq]

Hi Vortx, do a search for an article by Ubiquitous regarding this. It's the definitive piece, with photos and everything.

[vortx]

thanks! could still not get any blade in between, so I used a heatgun to melt the remains of the original plastic crystal. Had I just thougt of that earlier. My rehaut is now badly scratched on one side... Polishing job much.

[dbutlerman]

I just put a Clarks Superdome in my MBW 1665 and had the same issue as JMB. I just used a ring of Hypo and the base of the rehaut placed the crystal on it, but the compression ring was a little loose, so I put a touch of epoxy and 12, 3, 6 & 9 and glued the compression ring down. Anybody see any issues with this? I am sure I can still get everything apart if needed, just wanted to see what the opinions out there might be...seemed a little janky to me, but it did the job and it looks great!

[Dizzy]

I always put down a tiny tiny thin bead of GS-hypo.. place the crystal where you want it and lightly give it an 1/8th of a turn so make sure you have a good seal and no gaps in the glue.. then press on your retention ring. Should be sealed up nice and tight after that

dizz