There I am, sitting in a short meeting with a facility manager talking about the sanding process from start to finish. He tells me that they have issues with color consistency in finishing because their sanding process is not consistent. He says, “Anne Marie trains all of my sanding table personnel, but who trained Anne Marie?” I smile…..
Tribal knowledge at the wide belt machine and hand prep sanding table is the result of years of conditioning of the personnel through repeated cycles of crisis and stress. Tribal knowledge is rarely written down and often uses essoteric factors like feel and look to decide quality.
We sanded that job the way we always do but it isn’t right and the finisher is upset.
We didn’t know the job wasn’t right while we were doing it and we have no idea why it didn’t come out okay this time.
We will sand much more on the next job to be sure that we don’t miss anything or mess anything up.
We will do anything it takes to get the job out so we won’t get in trouble again.
If you can see how this cycle can produce ridiculously crazy ideas and processes then you are not alone.
The guard against Tribal Knowledge in sanding is the use of consistency and evidence that that anyone can look at and recognize.
When a cabinet door is wide belt sanded correctly, the goal of the next step in the process is often the removal of the cross grain scratch pattern in the rails and the reduction of the scratches on the stiles, resulting in a uniform surface finish that will take stain consistently. In some shops this is done via a machine. In most it is done via hand orbital sanding at the prep sanding table.
What happens next will vary just as much as the people doing the sanding. Most sanding tables have horrible lighting so the personnel cannot see what they are doing to the wood. They almost always use muscle memory to decide how much and how long to sand. They know that if they spend x minutes a side on a cabinet door they won’t get in trouble and the finisher won’t be upset most of the time. They may only need 1 minute or less on that piece but they cannot see when the wide belt scratch is all gone or they are not sure they covered the entire surface so they don’t know when they can move on to the next door.
Seeing the scratch pattern in proper lighting and removing it is a definitive act. Seeing the swirls you created through poor technique and correcting the issue is a definitive act. Seeing a shiny spot you missed because your orbital sander back up pad is not flat is a definitive act.
Tribal knowledge says that if you sand for x amount of time it a certain pattern you will get it all and it will be right. It feels smooth. It seems done right until the finisher gets upset and the stress starts all over again. Now we must sand x minutes plus y extra minutes so the finisher won’t get upset.
Which one of these processes do you think will result is higher production rates and less mistakes?
Adam West
Techdude@surfprepsanding.com
