Help installing mainspring

[Lc130]

Hi All

I'm a beginner and this my first attempt to install a mainspring on an automatic.  The movement is AS1700

I understand that I'm to place a small amount of braking grease to the inside of the barrel.  I've purchased moebius 8217.  Two questions come to mind 1) how much of this should be applied and 2) when I push the new spring in won't it simply push the wall grease to the bottom??

Here are pics of the old and new springs.

Many thanks for any help!

Charlie

 

[margolisd]

I'm a beginner too. But for what it's worth my method is this. I put on gloves and apply a thin coat of 8200 to the spring itself. Gently running it through my thumb and forefinger. I put a few dots of 8200 on the barrel wall and, as in the illustration below from Practical Watch Adjusting, 3 dots on the side of the coiled up spring. I use D5 on the arbour at the points shown in the illustration. Just a little dot is sufficient. It works pretty well for me.

 

 

[Klassiker]

Hi Charlie,

I did an AS 1700 myself not long ago, and I also bought a new spring, which is much easier than reusing the old one. You'll find that that holder it's supplied in is slightly smaller in diameter than the inside of the barrel. Just lay it on top (check the direction!) and push the spring carefully down into the barrel. As the spring escapes from the holder it expands into the barrel.The grease you put on the inside wall beforehand will be squeezed outwards rather than downwards.

I wasn't sure how to describe the right amount of grease, so I looked for a video on you tube and found this one - Classic Watchmaking: Barrel Wall Lubrication. He greases the barrel wall right at the end. The answer it seems is a HUGE amount! Certainly much, much more than I put in. Maybe some of our more experienced members can offer their opinions.

[Lc130]

Thank you both. 

I didn't plan to unwind it from it's package; just push it in.   I've read that some springs come lubricated with teflon.  As you can see the package doesn't state it.   Would you still recommend I use the 8200 (which I do have).

1 hour ago, Klassiker said:

He greases the barrel wall right at the end. The answer it seems is a HUGE amount! Certainly much, much more than I put in

Yes!  It does seem like a good amount.  

[margolisd]

Do you have a winding tool?

[Lc130]

18 minutes ago, margolisd said:

Do you have a winding tool?

Yes but its for springs that wind in the other direction.  

[margolisd]

Maybe see what the more experienced folks think. But I'd say pop it strait into the barrel.

[Klassiker]

19 hours ago, Lc130 said:

 I've read that some springs come lubricated with teflon.  As you can see the package doesn't state it.   Would you still recommend I use the 8200 (which I do have). 

if the spring feels dry to the touch then I would definitely add grease. From what I can gather, it's hard to over-lubricate mainsprings. You just don't want it leaking out of the barrel and all over the rest of the movement. Not enough lubricant on the other hand is bad. If you've got the 8200 then use it. I'd put a smear on the inside face of the barrel and the same on the lid, then two or three spots on the coils once the spring is in, like margolisd shows in his post above.

[margolisd]

I think the dilemma is whether to apply the 8200 along the length of the MS through the thumb and forefinger as I suggested. I normally do this but I don't know how much difference it makes. If he does this it means he'd need a mainspring winder to get it into the barrel which he doesn't have. If he skips doing this he can pop it right into the barrel from the holder it's packaged in.