Drying wood has always been a problem for most woodworkers especially for those w/ limited sources of properly dried wood. In my early years in woodworking I've had to buy green or air dried lumber then bring them to companies who dry them for a fee. Nowadays you'd be lucky to have access to one as the rules of drying now require you to have proper permits for the wood you wish for them to dry. For this reason I decided to build my own Kiln-dryer w/ a heat source and a dehumidifier system. This dryer is designed for two of the country's predominant conditions, HOT & COLD OR WET WEATHER. Hence my DIY KILN DRYER......
Re: DIY Wood Kiln - dryer
This Dryer has an Auxiliary Diesel burner w/c is fired only during the wet or rainy season when temperature drops in the 30 degrees celsius and below range.
Re: DIY Wood Kiln - dryer
The heart of the system is a 3HP industrial dehumidifier w/c dries the wood by sucking moisture in the drying chamber and converts the dried air to hot clean air to be recycled back to the chamber w/c then sweats the moisture from the wood back to the dehumidifier.
Re: DIY Wood Kiln - dryer
The heart of the system is a 3HP industrial dehumidifier w/c dries the wood by sucking moisture in the drying chamber and converts the dried air to hot clean air to be recycled back to the chamber w/c then sweats the moisture from the wood back to the dehumidifier.
Re: DIY Wood Kiln - dryer
The control panel houses the Temperature controller, burner switches, Air or fan controller as well as the Timers for single operator access only. The dryer operates 24 hours w/ a 5-hour interval switching and an hour rest for moisture equalization in the chamber.
Here's the Temperature controller...
Re: DIY Wood Kiln - dryer
Here is the air return tunnel w/c recirculates the dried hot air from the dehumidifier to the drying chamber.
Water from the air inside the chamber and those extracted from the wood are collected in a bucket w/c are measured to determine if our extraction rate is on schedule. Collection rate may vary from the type or species of the wood.
Re: DIY Wood Kiln - dryer
The unique part of this dryer build is the material used for the drying chamber and the Heater bed. I used an 18mm Flexboard (fibercement) so that the material can withstand heat and water exposure during the drying process. It is also easy to cut and seal w/ a suitable heat resistant coating like an industrial Aluminum Oxide paint or a high temp Elastomeric paint sealer.
Re: DIY Wood Kiln - dryer
This dryer can cook local hardwood like Narra, Yakal, Guijo and imported hardwood like Walnut, Oak, and Iroko. It takes about 10-15 days to dry 2" hardwood and about 6-8 days for softwood during the summer. Add 5 days for the wet season. Wood can be dried 9-12% MC but can be lowered to 6% MC if desired. For our climate 9%MC is just about right.
Re: DIY Wood Kiln - dryer
Willy .... do you save a lot when you buy green wood and dry it yourself? Just curious as this is the first time I'm seeing a kiln drying setup.
Very good informative post bro. Thanks for sharing.
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Re: DIY Wood Kiln - dryer
May i ask how much it cost to build that kiln?
Re: DIY Wood Kiln - dryer
Willy .... do you save a lot when you buy green wood and dry it yourself? Just curious as this is the first time I'm seeing a kiln drying setup.
Very good informative post bro. Thanks for sharing.
Thanks for viewing my post JayL. Green wood is only economical if you happen to acquire it by accident or free (Pedring, Ondoy) . Your money is best spent on semi-processed or sun-dried wood. Lesser hassle on reprocessing lesser labor cost.
Re: DIY Wood Kiln - dryer
May i ask how much it cost to build that kiln?
Hi Moji, at the time of the prototyping, 2008, 100k lang. I upgraded a lot of things in it so it is most likely in the 300k range na. When i first designed it diesel burner lang sya at circulating fan w/ manual switches and Temperature indicator lang. Three workers had to operate it on a per 8-hour shift per day. Now everything is automated. Flip the switch and it will run for 15 days w/ programed intervals of 5-hour extraction and an hour of equalization per day of operation. Most imported portable dryers like Nyle Kiln's have a tag price of about 2M (PHP) for their 1-2000 bdft capacity per 4-6 days drying. My dryer is designed to cook up to 5000 bdft per 10-15 days of drying. Near enough di ba?:)
Re: DIY Wood Kiln - dryer
Not bad! I guess that machine paid for itself with the work you do..
Re: DIY Wood Kiln - dryer
Not bad! I guess that machine paid for itself with the work you do..
Indeed, I used to pay 15-20 pesos per board foot for drying services. Now i am saving a substantial amount from drying and rejects from production are minimized adding more to our profits in the end. I designed this w/ the intention to encourage wood industry players to upgrade their quality of wood for the benefit of both consumers and craftsmen. A lot of talent is wasted on rejected products or eventual product failure ( warpage, shrinkage and checking).
Re: DIY Wood Kiln - dryer
Thanks for viewing my post JayL. Green wood is only economical if you happen to acquire it by accident or free (Pedring, Ondoy) . Your money is best spent on semi-processed or sun-dried wood. Lesser hassle on reprocessing lesser labor cost.
Great topic. Next to wood identification, I was hoping someone would start a drying thread. I hope others can share their info, whether air or kiln drying.
e.g., positioning/spacing, sun exposure or not, warp and check prevention (seal ends with wax? stabilizer? ethylene glycol [engine coolant] as stabilizer/insecticide/fungicide?)
rules of thumb -- one year per inch of thickness? 😮
I needed to learn more about air drying after I got some mahogany/acacia/gmelina/ipi-ipil from Rose Industries (mentioned by balarila and others previously). Their moisture content was all over the place, from about 11-26%, at least according to the limited sampling and meter I had at the time (planning to get a better meter). Clearly, the air drying needs to 'continue'.
BTW, around that time, I found another lumber supplier (Delta Wood warehouse) in same area (Pasig) that could give kiln-dried mahogany/etc. (both rough and S4S) for less than the air/sun-dried P60/bft of Rose. No need to 'continue' air drying those woods.
I designed this w/ the intention to encourage wood industry players to upgrade their quality of wood for the benefit of both consumers and craftsmen. A lot of talent is wasted on rejected products or eventual product failure (warpage, shrinkage and checking).
Cannot but feel sad for the industry and workers when out of a huge pile, one can only find a few pieces that are 'good enough'. Hopefully the industry is listening/improving...
