Weight of hive to estimate stores

[asol]

Over the weekend I used a luggage scale to heft my hives to estimate the stores.
The pickup point was on the rear of the hive via a screw into the floor and the fulcrum was the lower front edge.

All my hives were between 17 and 20Kg. They are all brood and half Cedar National, Mesh floor + brood box + super + crown board + metal clad roof.

In order to estimate the stores I obviously need to know the weight of the individual parts.
I have access to a super with frames containing empty but partially drawn foundation, this weighed 4.6Kg.
Bumping this up a bit to 4.8Kg to account for the partially drawn wax I also estimated the following:-
Brood box 7.2Kg
Crown board 1Kg
Roof 3Kg
floor 1.5Kg
Bees (20000 of them?) 2.2Kg
Total without stores= 19.7 Kg.
With stores measured= 2*17Kg (use minimum weight = 17Kg ) = 34 Kg

Stores= 34-19.7 = 14.3 Kg.

Does this sound about right??
I realise there are issues regarding scale accuracy and distribution of stores but for a first off guesstimate ....

 

[enrico]

I presumed you measured all the empty box's the same way by just weighing the rear.
Otherwise seems reasonable to me but maths never was my strong point. I just heft and think....oh that seems heavy enough!

 

[asol]

No. I only measured my total hive by hefting. This is why I've multiplied it by 2 as the real weight is twice the heft weight, levers and all that stuff....
The super + frames is the only thing I've measured on a set of bathroom scales.
Everything else is estimated.

Andrew

 

[enigmatica]

What a brilliant idea! I could easily make a set weighing scales based on a lever. Here's a pic of a baler I made this year, minus the bale chamber and with a support at the front that would work. Thanks:


Ok, here isn't a pic because I haven't posted enough!

 

[MJBee]

I have screwed a "cup hook" into the center of each side of the floor and weigh both sides then add. This IMHO gives a more accurate picture.

There can be a big variation between the two weights caused by the stores/cluster being biased to one side/front/back

 

[Luminos]

I have screwed a "cup hook" into the center of each side of the floor and weigh both sides then add. This IMHO gives a more accurate picture.

There can be a big variation between the two weights caused by the stores/cluster being biased to one side/front/back

 

[asol]

I have screwed a "cup hook" into the center of each side of the floor and weigh both sides then add. This IMHO gives a more accurate picture.

There can be a big variation between the two weights caused by the stores/cluster being biased to one side/front/back

When you say "big variation", how big?

 

[Davelin]

For what it's worth;

I have deep national cedar box with deep lids and I like to get the total hive weight up to 35-40kg. This has given enough winter stores for me so far.

 

[Davelin]

When you say "big variation", how big?

I find it can be up to 2-3 kg difference, I have hooks either side.

 

[Finman]

.
Every one has his own furnitures.

When feeded, open the hive and look how full it is food. There usually brood too which is very light.

When you find a well feeded hive, take from it a standard weight. Then you know what it is.

.

 

[BILL.HEARD]

I heft on both sides of the hive, if it feels nailed to the floor that good enough for me. i will heft again in March. I have just finished feeding the last of my hives with syrup, I don't mess around with fondant.

 

[itma]

I use a "cleat hook" half way along each side of the floor - but you could use a half-driven screw, and refine that with a washer ...

Weigh both sides and add them together. Yes they aren't always the same!
That gives you the total gross weight.

What I try to do is estimate (visually, during inspection) how much stores there are on each frame. 50% here, 10% there, 0% sometimes. And add them up.
Lets say you get 500% - that's equivalent to 5 full frames worth.
The rule of thumb is that a national brood holds 5lb. So, 5 frames means 25 pounds of stores.
Subtract that from the measured gross total weight and you will have an estimate for the weight of the hive, frames, etc.
Do this a couple of times and average the hive weight estimates.
Then when you are no longer opening up, you can use that average to calculate the weight of stores in the hive.
Easier to do than describe!

If you change the config of the hive (different roof perhaps, adding a super of insulation, or whatever - just weigh the hive immediately before and after the change (twice on the same day). That will reveal the change to apply to your net hive weight.


Another thing to watch out for is that wooden hives will soak up some dampness and gain the odd kilo themselves. So don't trust your measurements to any great precision - act before it gets too empty!

 

[Excession]

I weighed mine with a digital scale, both complete hives (brood and a half - half being stores fed back). Both weighed just over 29kilos.
This was complete hive suspended, not hefted.

As it was 18 degrees I did a last check to see what stores they were carrying, and there was quite a bit, but I am still feeding.

If anything, it gives me a measure as a starting point.

Interesting to compare our weights though.

 

[madasafish]

All too complex for me. I heft a known empty hive (with comb but no bees or stores) and then a live one.. If it's a lot heavier- it's OK. If not it ain't.

"a lot heavier" means my back hurts...or protests. (which is why I do yoga and don't lift nationals unless I have to at our Association apiary)

 

[Dishmop]

I find that looking inside is quite good.

 

[asol]

I find that looking inside is quite good.

I suppose though looking inside is still prone to errors.
An uncertain Kg per frame and estimations as to % of frames full.
Surely the advantage with hefting (or weighing) is that you don't need to go inside, and its far quicker.
Even if I went inside I reckon my errors will exceed hefting / weighing.
With respect to estimating stores is looking inside really any better?
Andrew

 

[Davelin]

Well what I did was:
Looked through and estimated approximate stores 3 weeks ago.
Then started apiguard which finishes at end of this week.
Did a big feed last week when 2nd apiguard went on, amount of feed based on previous estimate, bearing in mind they are working ivy at the moment. When that finishes will weigh and top up feed if needed.
Haven't looked inside since start of month and don't intend to now.

Not saying this is right or wrong, this is just what I do.

 

[MJBee]

When you say "big variation", how big?

Looking at past records the biggest variation I have had was 4.25kg (over 9lbs) but that was in mid February - all the bees and the remaining stores were all in the RHS of the hive.

As Davelin said if you feed a hive in winter configuration of -OMF Brood box Solid cover board and roof - to weigh between 30kg (single National) and 40kg (14 x 12 and Commercial) they will over winter just fine. I weigh weekly from early February when the queen (usually) starts laying again. As soon as the hive has brood to feed the weight can drop very quickly if the weather prevents foraging.

 

[richardbees]

When you say "big variation", how big?

With frames 'the warm way' i.e. parallel to the entrance, I've found no difference with the weight either side but with frames at right angles to entrance maybe up to 5lbs difference.

I look for 60lbs Nat BB / floor / crownboard

 

[REDWOOD]

This all seems a bit complicated, just place your hive tool between the brood box and floor and push down, common sense will tell you that the more pressure you need on the hive tool to lift the box the more stores you have. Try it on an empty hive and then put a few bricks on top and try it again, you will soon get the feel of it, you only need to move it a few millimetres