Question
Does anyone have experience with orbital sanding machines? What are the pros and cons of these machines. Do they do a good job of removing the cross-grain scratches from cabinet doors and face frames which have been run through a widebelt at 180g? We currently have 3 people doing whitewood sanding and we want to automate some of the process. Any advice is appreciated.
Forum Responses
(Finishing Forum)
From contributor R:
Generally, these machines’ greatest strengths are sealer sanding and edge breaking. There are multiple head machines made by the likes of Heesemann that can do what you want, but look at prices starting at $100k and up.
If you do buy a sander like Kent be sure to get enough products to test from suppliers to get the combination you need for your finish requirements. The silicon carbide product may provide a little darker finish on your wood but you can do the adjusting in your stain.
We assemble our face frames with the pocket-hole system, so therefore we need to remove a fair bit of material through the widebelt in order to get the joints flush. We have a 2 head Cantek on which we pass the frames through twice. The first time is 80g - 120g, then we change the paper to 150g - 180g and pass them again. We outsource our doors and they come in sanded to 180g.
From here everything (including the doors) goes to the hand sanders with orbitals to clean up the cross-grain scratches, soften the edges, etc. What we are considering is instead of going to the hand sanders the parts would go to an orbital machine (similar to yours) and then through a "fladder type" brush sander as a final finish sanding and to break the edges of the doors.
What has your process been and what have you eliminated with the orbital machine? You mentioned the first head is a "combination" widebelt. What is that exactly and do you feel it is necessary before the orbital pads? What grit are your doors sanded to before they go to the orbital? What series of grits are you running on the orbital with what species of wood? Does the orbital completely remove the cross-grain scratch? What else do you do to the door after the orbital?
Someone told me that the Timesavers orbital machines were hard on bearings; did you have any problems? I know these are a lot of questions but I would really like to have some input from someone who is actually using an orbital machine for the same purpose that I have in mind.
The orbital has eliminated the extra step with the 220 belt because the machine has the combination widebelt head as the first head prior to the orbital pads and we run the 220 belt on that first head. So, the 220 final sand is completed at the same time as the orbital sanding.
The "Combination Head" on a widebelt is one that has both a contact drum and a graphite covered felt platen. This allows you to hit the panel twice, once with the contact drum, and then with the platen, all in the same pass. The platen produces a softer scratch pattern in my opinion, and reduces the chatter or wash board effect sometimes produced by a contact drum.
The next step ideally, would be a fladder sander just as you described, and unfortunately we haven't found one yet, so we still have to ease edges by hand. We have been running the doors through the orbital twice on the face, and once on the back to ensure that all cross grain scratches are removed.
We are using 100 micron sandpaper on the orbital heads. I believe the equivalent standard sandpaper grit is about 150. When we change paper, we put the old paper from the first head on the second head, and put new paper on the first. This gives us the same effect of using two different grits, but only requires us to purchase one. We use the same grit sequences on the widebelt and orbital regardless of species.
Generally speaking, the orbital removes all of the cross grain scratches. Occasionally, we will have a panel that is slightly thinner than the rest for some reason, and then there are still some scratches left. We haven't owned the machine long enough to know about the bearing issue. I do know that the orbital heads must be rebuilt from time to time. Our machine has 10,000 hours on it, and has had the heads rebuilt twice.
Comment from contributor B:
You might try looking into brush sanding as well. This machinery is generally more versatile than orbital machinery, allowing you to finish and sand raised panel doors in one shot. There are also linear machines available which would work well on your face frames. I would suggest checking out Opti-Sand, Loewer, and Costa.
