Thread: Bandsawing a Spotted Gum

No worries Paul

Just knew that it was there but must admit, I had to work out how to use it , don't think I've used it on here before

Some pix as promised (threatened?).


spotty 6 006.jpgspotty 6 001.jpgspotty 6 002.jpgspotty 6 003.jpgspotty 6 005.jpg

As you can see, it is not rocket science. The primary problem is holding down the plastic against the wind. The 150mm pipe is quite heavy and it is rolled around the plastic. This is easier to do at the sides. The ends are a problem as there is additional material all prone to catching the wind and acting like a sail.

There are small stakes hammered into the ground to resist movement of the pipes. Of course if I didn't have the pipes I probably would have used similar sized logs.

I need access which will be from the front (pic 2) to take moisture measurements.

How will it all work. I'm hoping for a good result but it is what it is. At the moment there is minimal air flow and no provision for the removal of moisture. I am planing to put some small fans in place and introduce a hot (hotter) air flow into the kiln area. This will create the all important air circulation as well as lifting the temperature. To some extent the moisture, because there is only a dirt floor, is absorbed, but I doubt it is efficient or sufficient. However in it's defence, the essence of a solar kiln is still gentle drying with, of course, unavoidable "spelling" during the night, which involves some re-absorption.

I may have to introduce some ventilation also at a later date.

The next step is for me to move the pile of logs (old power poles) behind the stack so I can site the "hot box."

Regards
Paul

I should have mentioned that I intend to place some temperature sensors in both the kiln and the "hot box." I am anticipating that the kiln will add about 10C to 15C to the ambient temp. It is a bit like the water in your garden hose. There is a practical maximum to which it can heat before it gives up its temperature to the surrounding air.

It would be different if the kiln was insulated. I think +20C would be the norm.

Regards
Paul

I had to make some modifications to the structure. Two days ago I moved all the concrete off the stack and moved the iron inwards so it is clear of the plastic. That was an ordeal. It was hot and humid in the kiln. Ugly! I don't think I will have to worry too much about not making temperature.

spotty 6 001.jpgspotty 6 002.jpg

Today it was apparent a combination of the wind and drawing the plastic tight had moved the end frames inwards allowing the plastic to contact the stack.

Drying kiln 002.jpgDrying kiln 004.jpg

So I placed timber battens across the top of the frames (on the underside of the pipe). This seems to have done the trick for the moment, but I suspect it will need further reinforcing to counter the effect of the wind. I'm not quite sure how I will do that as I am now in uncharted territory. The previous solar kiln I made as nowhere near as high and didn't provide the same level of wind resistance.
Drying kiln 005.jpgDrying kiln 008.jpgDrying kiln 009.jpgDrying kiln 007.jpg


I also took the opportunity to put some protectors on the top of the star pickets as it is possible they will chafe on the
plastic.

Drying kiln 012.jpgDrying kiln 011.jpg

Next stage is to make the "Hot box" and add some forced circulation to create airflow. That's a little way away as there is a list of things considered essential by SWMBO that have to be done first .

Regards
Paul

Doing well there Paul!
Poor old Fergie! A lot to ask of a relatively unsophisticated hydraulic system.

I had a Horndraulic loader attached to my old 65Mk.2 had to fit a two way lock out valve
and several extra levers to be able to use front and back implements separately.
In my case I used the front end loader to lift bins of oranges onto the old TJ Bedford.
Made Myself a set of TPL forks that I sat a full bin of oranges on as a counterweight.

Hi Paul, by hotbox I assume you mean an auxilliary heat supply with fan/s to move air out of and into the main kiln, I made up what I am calling a mini solar kiln which could be either a stand alone unit or be incorporated into a larger system like yours, one day I plan on doing something similliar with mine.
A few pics of the mini kiln.....
plenty of room for veneers.JPGairflow baffles.JPGhot airflow baffles.JPGwith the glass front.JPG

From memory I think it reached well over 50°C, I used an old stove range hood fan and two shower screen doors.


Pete

Originally Posted by artme

Doing well there Paul!
Poor old Fergie! A lot to ask of a relatively unsophisticated hydraulic system.

I had a Horndraulic loader attached to my old 65Mk.2 had to fit a two way lock out valve
and several extra levers to be able to use front and back implements separately.
In my case I used the front end loader to lift bins of oranges onto the old TJ Bedford.
Made Myself a set of TPL forks that I sat a full bin of oranges on as a counterweight.

Arthur

The main issue with the Fergie is the 3PL hydraulics are linked to the clutch and the PTO. If the clutch is down the hydraulics don't work. A further complication with mine is that there is a fault with the hydraulics whereby there is no positioning possible,. The 3PL is up or it is down. Not even as versatile as the Grand Old Duke of York as there is no halfway position. A few other additional idiosyncrasies really get my blood boiling.



Regards
Paul

Originally Posted by pjt

Hi Paul, by hotbox I assume you mean an auxilliary heat supply with fan/s to move air out of and into the main kiln, I made up what I am calling a mini solar kiln which could be either a stand alone unit or be incorporated into a larger system like yours, one day I plan on doing something similliar with mine.


From memory I think it reached well over 50°C, I used an old stove range hood fan and two shower screen doors.


Pete

Pete

Yes the principle will be very similar, but not as smart looking as yours. I have a couple of fans out of a commercial soft drink fridge, which I am looking at using. The main issue is distributing the air across the drying stack. I'm not sure if they will create sufficient flow as they are not large.

Regards
Paul

What about those roof-type whirly-gigs?
If you put one on top of a large-diameter tube/pipe you could draw air out from any height from the ground upwards???

and someone ... can't find it now ... mentioned air-slots low on one side and high on the other ... any use?

Paul
ps ... "I know nothin-k" ...

Originally Posted by pmcgee

What about those roof-type whirly-gigs?
If you put one on top of a large-diameter tube/pipe you could draw air out from any height from the ground upwards???

and someone ... can't find it now ... mentioned air-slots low on one side and high on the other ... any use?

Paul
ps ... "I know nothin-k" ...

Paul

Yes. It has given me food for thought. I even have a spare whirly whatsit somewhere. The issue is that it takes heat as well as moisture, although as you said the pipe could be taken from close to the ground.

Regards
Paul

My first Fergi had exactly that hydraulic set up Paul. Regular PITA. Worst thing is that it is
impossible to modify them.

I guess any later model of any brand tracor would do the job. They should be cheap enough
to acquire and fix.

It is well overdue for me to post some latest drying figures. I had planned to do this on a more regular basis, but I get easily distracted:

Timber	Size	Surface reading	Centre reading
Spotted Gum (first batch)	100 x 50	9% (20%) {49%}	18% (54%) {>70%}
Forest Red Gum (sample 1)	100 x 50	7% (12%) {13.5%}	9.5% (13%) {14%}
Forest Red Gum (sample 2)	100 x 38	8% (12.5%)	(13%)
Spotted Gum (second batch)	125 x 25		9% (45%)
Spotted Gum (second batch)	200 x 50		16.5% (55%)

The figures in the first set of brackets date from 30 August last year and in the curly brackets from 4 June.

I don't think there are any surprises here.

The 25mm Spotted Gum boards would be ready to use so drying time for them has been six to seven months. The Forest Red Gum is also ready to use, but it started off a lot dryer. More time still required for the 50mm thick Spotted Gum.

Perhaps the most interesting data is for the the first batch of Spotted Gum where the moisture gradient between the surface and the centre of the board illustrates the fundamental issue in drying timber successfully.

One other comment in regards to the Spotted Gum is that the second batch of timber has dried more quickly than a similar thickness from the first batch. The second batch is at the top of the pile.

I measured temperature inside the kiln (I use the term loosely for what is no more than a piece of plastic. It was two degrees hotter inside at ground level than ambient, but four degrees hotter where the top sample board was measured.

Clearly this is an airflow problem. I started to build the "hot box" and fan forced airflow, but more distractions have prevented me completing that.

Regards
Paul

Originally Posted by scottmac

Ive got a dinosaw bandsaw and a chainsaw mill. A mate has a lucas so i've never got around to setting up the bandsaw as it needs some repairs. once i've got my shed worth of timber done (build a shed) i will probably set band saw up for small jobs on the fly as a permenant mill at my place. do you thing it's worth it with the other mills available yet need set up each time? Are they much faster than a chainsaw mill? Would you use quarter sawn for a kitchen bench top for tight grain feature and less spring/cupping etc? really enjoyed seeing and hearing about your bandsaw work and very nice work.

hi scotty
have you still got dinosaw mill
with thanks mark