levelling a level

[Steve Friedman]

+1 on the Stabilla, but aren't there adjustment screws on the level?

Steve

[David Wadstrup]

No, no adjustment screws. There are 4 screws that attach the top brass plate to the wood body, and 2 screws each holding the brass feet on the bottom. NOne of them, as far as I can tell, serve to adjust/calibrate the level.

[Mel Miller]

I would doublecheck the reference surface by reversing your reference level, and if that level is very sensitive (like a Starrett 98) be sure to keep your warm hands off the vial in the process. I can think of no conditions when your torpedo level would read level one way, and off level when reversed on a true level surface.

Mel

[Gaz Palmer]

Hi David,

Rabone boat levels (Mahogany or Rosewood depending on age) are nice levels to use, but need a lot of tender loving care and the means by which they're best adjusted typically involves re-setting one or both of the brass tips to the underside of the level, unless the bubble is loose in it's bed. The underside of the level can certainly be re-faced or trued, but the two brass tips are the bearing surfaces/points on levels of this type and can be re-set by re-finishing, shimming, or replacement, but you need an absolutely level surface (Typically another level known to be true) on which to gauge and make your adjustments. Touching onto vial adjustment on levels of this nature (Rabone wooden levels) are set into a cured putty/plaster of paris-like material) tends to lead to a world of headaches.

As mentioned earlier, an alloy bodied Stabila will remain true throughout it's length during a lifetime of use and a Type 83S can serve as a reference when adjusting other levels.

[John Coloccia]

David: the situation you're describing doesn't really make sense (which is why you're posting here...it's confusing you too!). Something in one of your assumptions is off. If you're curious and want to get to the bottom of it, please post your exact procedure for doing this test. I know you're using a shimmed straightedge for a reference surface, and I can't help but think that something has crept into this that is throwing you off. Also, are you using a digital level as your reference?

[David Wadstrup]

HI Gaz,

Thanks for sharing your thoughts. It is a nice, but delicate level that is in good shape. I believe it is mahogany. Any idea of the age?

Like you suggested, I had planned on adjusting the feet to recalibrate. With either shims or trimming. But when I found that I was getting different readings, one of which showed level, I couldn't figur out what to do. If I tried to shim up the low side when it read out of level, it would bring it out of level when it was oriented in the way in which it read true. Confusing!

I'm starting to assume that perhaps my reference surface is not as level as I think it is, so I ordered myself a Stabila torpedo level to make absolutely sure. Should be here in a few days.

I'd love to hear more about this company and the levels they made. Any sources of information that you could send my way?

I appreciate it,

David

[David Wadstrup]

Good morning, John,

Thanks for the offer of help. I've got a Stabila on the way to make sure my reference surface is absolutely level. It is not a digital one. Would you mind if I got back in touch once I've checked? I'll make sure to give a step-by-step recounting of my procedure if I'm still getting these non-sensical results.

Thanks,

David

[john brenton]

That antique is a very nice level. I also have a stabila that I used everyday and took some serious beatings. They are good levels. I would see what the stabila does on that surface, and if it does the same thing then you know your surface is not that great of a reference.

If you did decide to take on the task, I would use some sandpaper and stick it to that surface plate and see if a few very light passes wouldn't fix it.

[David Keller NC]

David - One aspect of this litte mystery is the color of the level vial in your picture. Old level vials were clear - the fluorescent green/yellow coloration is a relatively recent phenomena. J. rabone and Sons were in business a long time, so it's possible that your level is of 1960's or 1970's manufacture and the vial is original to the level.

But it's also very possible that the vial was broken at some point and replaced. I see that a lot on the antiques market.

All level vials are curved along their length to some extent, although that might not be immediately apparent by eye. This is the principal difference between a "fast level" (low curvature), and a "slow level" (high curvature) of the same length. It's possible that the vial in your level has uneven curvature, which would make it much more sensitive on one side relative to the other, and would potentially result in the effect that your seeing.

Unfortunately, if the level vial is mis-shaped, you can't fix the level by working on the two brass bearing points - you will have to replace the level vial. That can be done, and you can purchase spares from several antique tool dealers on the web.

[Peter Cobb]

All level vials are curved along their length to some extent, although that might not be immediately apparent by eye. This is the principal difference between a "fast level" (low curvature), and a "slow level" (high curvature) of the same length. It's possible that the vial in your level has uneven curvature, which would make it much more sensitive on one side relative to the other, and would potentially result in the effect that your seeing.

You beat me to the explanation... I was thinking along the same lines, or rather curves.
Cheers,
Peter

[John Coloccia]

If everything is truly level, the orientation if the level and shape of the vial shouldn't matter. Where it would matter us if you were trying to measure inclination. If something is shaped poorly, the markings will need to be calibrated and the rate of change will not be consistent.

[Brian Vaughn]

Actually, the situation makes perfect sense if the sole isn't parallel to the vial, and the surface is barely out of level. In one orientation, the skew of the vial counteracts the skew of the sole, resulting in an apparently level display. In the other orientation, the two skews add to each other, resulting in an apparent out of level situation. Think of it like this: > In one orientation on a sloped surface, the top line would be level. In the other orientation, on the same sloped surface, it would be twice as out of level.

[Brian Vaughn]

By the way, the best way I know to check levelness of a surface, in the absence of your new Stabilla, is a large glass marble. As an appraiser, I used to carry one with me to check floors, and it quick and easy to use.

[David Wadstrup]

Brian,

You're interpretation makes sense to me. It's the first possible explanation that I can actually wrap my head around. Thank you! The Stabila should be here on Wednesday, and I'll make sure to eliminate any errors in the reference surface.

David,

It is a yellow/green fluid(a color I strongly dislike). Does that date the vial to 1960s+? I would have thought it was an earlier level(although my assumptions were made without any real knowledge of the subject). I'm hoping that my reference surface is out of level and that the sole of the level is out too. Like Brian said. This would make it an easy fix. I don't know if I want to get involved with trading out the vial. Sourcing one and chiseling out the old vial seems like a major headache. Although if I could replace it with a vial with better looking clear fluid....

Thanks, everyone,

David

[David Keller NC]

The dye is apparently Fluorescein, which was first synthesized in 1871. However, it's apparent that it wasn't commonly used in levels until much later, as there are many levels on the antiques market with known manufacturing dates well after the 1870's. My guess (and I'm no expert on this - you would need to talk to someone that's really into collecting levels from the MWTCA) is that it was probably not commonly used until synthetic organic chemistry was industrialized in the 1950's.