Bandsaw modification for green wood

[Woodturnerjosh]

I have a Woodfast MBS-400 which has plenty of power and capacity for what I need but I find the bearing roller guides useless on green timber. They tend to gum up with sap and just press the green wood onto the blade, requiring lots of cleaning after use.

I looked into retro-fitting some ceramic guides and while this is possible it's also an expensive avenue to go down. The easiest solution is to simply remove the bearings and use the bolt to secure a square block of hard timber (I used a scrap piece of bakelite) and this does the job perfectly! No sap and green wood pressed onto the blade and no bearings to clean off after use! I still used the rear thrust bearings as these are not an issue.

The supplied bearings are great on dry timber but for wood turners using green timber I think the Euro style guides would be better. I actually had this problem on my old 14 inch bandsaw as well and ended up swapping the nice bearing roller guides for cool blocks.

I'd be interested to hear if anybody else has had similar issues or has found a different way to deal with the issue.

Josh

372968

[joe greiner]

I haven't done any comprehensive tests, but I keep a stock of surplus candles on hand. I cut a candle before each wood-cutting session. Seems to help a little.

Cheers,
Joe

[BobL]

I mill very green (sometimes felled yesterday) timber using a bandsaw with a 2" wide 5.3m long band (35" wide cut). The band guide bearings are just Wandoo blocks and the band is water cooled direct from a running hose. Even after a day of milling there is nothing on the band.

At home I have a19" CT bandsaw with the standard bearings which I occasionally use for milling short green logs. I don't use any lube and rarely see any resin on the bearings but do occasionally see some resin on the band if the TPI is too high. When this happens I apply a light spray of diesel and after a couple of hours the resin comes off by cutting a piece of dry Jarrah. Polyurethane tyres are highly resistant to diesel so it won't worry the tyres. Resin gets to the bearings by being carried there on the band and resin on the band indicates the cutting process is on the hot side. Typically this happens when the TPI is too high and sawdust is not being cleared, band has become blunt and/or lost set.

Conventional upright bandsaws are not really optimised in terms of band speed for cutting green timber because their band speeds are a bit low (e.g. 3000 fpm). Provided a sharp Low TPI band is used something like 4500 - 5000 fpm works better as it better clears sawdust from the kerf.

Conventional bands don't always have enough set. Green timber is more fibrous that dry timber so the the inside of the kerf contains lots of fluffy dangling sticky fibres that act like little paint brushes and constantly paint resin onto the blade. The hotter the cutting process the more resin is forced out of the wood. If the blade has a bit more set then the slightly wider kerf will put less resin onto the band and subsequently onto the bearings