cornish wood burner

You obviously didn't allow for the Cornish weather we've been having.

No idea what the machine is or how it works, but if you have something like a joystick control you probably have micro switches on the driver end of things. They are used for many things but have a frequent failure rate in my world.

Just taken the samples out of the oven and weighed for the last time. The largest 480g sample lost a couple of grams over the last hour but close enough now. Scales were checked for accuracy with increasing weight and were within 2 grams over 800. Two sample logs one 7 inch dia 6.5 long other 9 inch dia and 8 inches long. Large log had 16.9% mc in the centre sample 17.5%mc in the outer sample inc bark Small log. 18.77% mc centre 19.1% mc outer The small log didn't split suddenly like most of the larger ones so I can only assume the extra moisture made it less brittle. All logs were stacked with gaps to allow for air circulation. As I've said previously 15 months open air seasoning and 30 months in the shed. As the smaller one was wetter and the outsides of both wetter than their centres it suggests to me that both are gaining moisture from the air. Moisture % calculated on a wet basis as normal Looks like Aunt maud has won the coconut.

A1 advice Jon

Testing them now John. 2 1/2 years after being ringed up and almost 4 years after felling. Split today for testing. Weighed, now oven drying so I won't know the results until tomorrow.

I suspect you will be a lot closer than Jon. I have weighed 4 samples from 2 logs. 2 centre and 2 outside samples. All are drying in a slow oven at present.

Anyone care to guess what moisture content will be for this ash. 8 inch diameter air dried for a year or so outside then logged in the summer and stacked at the back of an open shed for 2.5 years

The ash in question has severe shrinkage cracks so presumably its lost some of the bound water over the years which has tightened the cell structure. For my own interest I might do a moisture check on a couple of these pieces. I also have some lengths of smaller diameter of the same age under cover so I expect that will be similar. What surprised me was the brittleness of the straight grained pieces. Knots are actually a help as then it seems to split slower and I do not need to retrieve the pieces from across the shed. In future I will try and split the ash before it gets to this stage. It's good to understand what's going on, thanks all.

So it's the lignin drying and hardening over time making it harder to split?

Know what you mean, we cut down a eucalyptus many years ago and as you say doesn't get easier with keeping. We had a bit left that we used wedges on in the end. It was the muzzle velocity of this ash that surprised me. You wouldn't want to be in front of it. Other pieces I split after a couple of years and they were very easy. Amazing difference.

I've just been splitting some 6 to 12 inch ash that has been in the back of my shed for a few years. Almost all needs the full 8 tonne of my splitter, then it goes off like a gun. I kept these rounds intact for ease of handling but I'm having a rethink on that. Is it the sap hardening doing this?

Hi Daythe trees. Decide what implements you need to buy for your jobs and work back to give your tractor size. For example if you need the reach and power of a farm contractor type hedge trimmer then that will rule out a small 40hp tractor.

As Jon says the idea of diesel is to make the bitumen tacky again then it will bind together.

Why not season before you chip your wood or is it arb waste chip? Our chip doesn't lose much moisture in our unheated shed but you have the advantage of heat so worth a go I would think. On the rare occasions I've had room to turn it the surface dries presumably by air movement but the bulk seems virtually unchanged. If you could get air through it I expect that would be best.

In my day job we normally call the distribution board or cabinet mcbs "breakers" and any motor protection devices such as you have named "overloads". Sorry for the mixup but it's common terminology with the engineers and electricians I deal with.

A household breaker trips in a quicker time than a motor rated breaker. The motor rated one is designed to trip slower to allow for the large starting current. Neither are designed to protect a motor. Both are thermally activated. A motor should be protected by a motor overload which needs to be adjusted to maximum running current found on the motor plate. Again thermally activated. For example a motor with a max running current of 5.9A could have a motor rated breaker C20 to protect the cable. C is trip time 20 is current carrying capacity. A heavily loaded motor with a heavy load such as a compressor might need a D rated trip to allow a longer start time drawing a high current. The motor will be protected by a motor overload which on installation will be adjusted to 5.9A. This allows for the heavy start current but if the motor stalls the overload will trip to protect the motor. Overloads are infinitely adjustable, breakers are available in set ratings.

I thought pleaching was layering.

Obviously opinions vary and mine must be in the minority here but I think a pollard is ugly. Worst thing anyone could do to a tree imo.

As Farmer Tom said its a rule of thumb. Not strictly true as depending on motor design starting current can be 10 times running current. It's just a useful average. When a motor starts it has virtually a short circuit through the windings, as it runs up the back emf opposes the incoming current which quickly drops to normal. This is why you probably have b rated breakers in your house but a motor needs slower acting c or even d rated breakers. A breaker size of 2 or 3 times running current normally does the job but do not over size as its job is to protect the cable not the motor as many think. Bigger gensets have more power, heavier windings, bigger breakers and more inertia to help cope with the high motor starting current.

Most of our works heating is underfloor but I use a slightly different system for timing. The office MUST reach a tropical temperature for long enough to warm chairs,cups and pens before occupation so it runs from midnight to just before end of play. The production staff are more forgiving so the concrete slab gets a couple of hours before start of work to melt the ice so all is well then. Best advice I can give to Mac and anyone installing biomass is make sure your heat store is big enough. It will give you much more flexibility to run the system as you want.

Looks like it may be a 2.2KW motor so more than 4KW generator. Go smaller and you risk pulling the voltage down which would risk damage to both machines

Motor starting current is about 3 times running current so go double your plate wattage.

Relief valve stuck open or seal broken up perhaps. Have you a reasonable flow but with little pressure? There should be a filter in the system somewhere so worth checking.

Have you tried just running the underfloor slightly over temperature by day and have a timer to turn it off by night. Depending on slab thickness it should retain a fair bit of heat for the morning. Probably not an ideal solution but if the morning and evening temperatures were bearable then no cost involved. I do something similar to this to reduce peak loads in the glasshouses.

Hi Mac If it helps a 2000ltr tank will hold 47KWhr of heat with a flow and return differential of 20 deg. If you need more info on recharge times with a certain boiler running set load for a certain time etc, or even system resilience running a smaller boiler than the peak heat load please let me know.