We are looking for a used six head moulder. Which type of moulder is suitable for moulding dense, moist wood?
(Solid Wood Machining Forum)
From Dave Rankin, forum technical advisor:
When you run wood that is moist, green, or very wet, I have had the best results with through-feed moulders. Since most of the through-feed moulders are of the same basic design, most any of them will do the job. The use of the proper feed roller makes as much difference in the ability to feed the material, as does the type of machine. The machine needs to be aligned correctly and the beds need to be lubricated with a fast drying lubricant. I would avoid any bed lubrication that cans wax when running wet lumber as it can gum up fairly quickly and then reduces the ability of the material to be fed through the machine.
Be aware that wet lumber will cause the machine to rust and this can cause a long list of problems. Clean the machine regularly and use lightweight oil (I use Thrust) to keep the rust down. Do not use WD-40 as this will not prevent the rust from occurring.
Over the years, I have been involved with rebuilding several machines that were in fires. The machines were sprayed down with WD-40. The result was a much more involved repair and higher costs to bring the machines back into condition. It should be noted that the machines were only wet from the putting out of the fire.
If you will also notice, the sprays that I recommend were not tested by the magazine article. These sprays are ones that have been located while doing different rebuilds and service calls. The customers that introduced me to these different sprays had rust problems with other sprays including WD-40.
It is my desire to only make people aware of what I have seen and used in an attempt to avoid some of the potential problems that may be experienced. I do enjoy a good discussion and would be very open to the research and evidence that offers alternative answers and solutions to the lubrication and rust discussion.
The largest problem that I have discovered with some sprays and liquids is when a vertical adjustment is sprayed. WD-40, for example, does a good job of cleaning the adjustment and providing a very temporary film that helps to break the adjustment loose. The area is cleaned to the point that oxidation occurs.
During my first years as a machinery technician, I used WD-40 regularly. After having to re-clean machine parts a second time before I could assemble them, I asked many people what they had seen with this liquid. One of the first to begin explaining the problem was a former military Army Ranger. He had cleaned some of his personal rifles with WD-40 and put them away for a couple of weeks. When he got them back out, the barrel (inside and out), and the other blued metal parts were rusted. After watching this happen, I did a test in my shop. After that test, I no longer use WD-40 or sprays that do not provide a permanent lubrication film.
Horizontal surfaces seem to hold the residue better than vertical surfaces. If you have problems with most sprays, you can follow them with a light coat of 10wt oil. I use Thrust in place of 10wt and seem to get good results in the US and Canada. Thanks for the input and make it a great day.