Floor Sanding

Ok, you have been staring at your hardwood floors for some time now thinking to your self “how am I ever going to get this floor looking nice?” “how am I going to afford to do this?”

Don’t panic, you can do it for a lot less than you can imagine. Normally a 12 by 12 room will cost less than $200 including finish. The key investment to “do it yourself” hardwood floor refinishing is time. Time will be your main investment. So, let’s talk about what I mean. Sanding wood is not magic and does not require years of training. Most floors needing refinished have an older finish mostly made of pinesap and a solvent called Varnish. The key to sanding is to understand what you are trying to accomplish. So, you want to remove the older finish, level the floor (remove cupping) and refinish with a new modern finish.

So how do we remove the older finish? A drum sander is your best bet with older finishes. A drum sander will provide a few advantages over random orbital sanders (this is a generalization because there are times that a random orbital sander is best and it would be better to show us pictures of your floor and let us help you choose the best sander for your job.) The older finish, when heated through sanding, will start to liquify and start to gum up the sandpaper. Basically, it starts to stick to the paper, reduces sanding efficiency and eventually may burn the floor. This gumming increases the time to sand the floor and also increases the cost by using more sandpaper, rental time and your personal time. A random orbital sander is in constant contact with the floor finish. Think of it this way, a commercial orbital sander is like a giant palm sander. It will build a lot of heat just through friction against the floor. A drum sander is a large rotating drum that contacts the floor once each revolution, thus it is cooler and removes the material without heating the floor finish.

So, let us talk about sandpaper. Sand paper is really a piece of paper with pieces of abrasive adhered to it. Yes, a little more complicated than that, but that is the idea. So, the misconception of sanding is that you are smoothing something down. Sorry, that would be wrong. Think of the little pieces of grit like little tiny saw blades. So, each time it makes contact with the finish it cuts a little piece away. Multiply all the grit and the speed of the sander drum and you can see the finish being removed. So, I believe the biggest mistake that people make sanding their floors is not thinking of the paper as cutting the finish off the wood. When you cut something with a blade sometimes it takes more than one pass. Like a saw is moved back and forth across a log and with a little time the log is cut in half. Sanding is similar in that you do not want to remove all the finish on the first pass. The first pass will just scrap and scratch the finish, the second will remove more finish, etc. Always drum sand with the grain. When all the finished is removed and the floor is flat it is time to change grit.

Basically, you start with the course grit and continue to the finest grits. The only purpose of the lesser grits is to remove the “cut marks” from the courser grits. So, all the work is done with the courser grits. There is a lot more to talk about, but I will cover that over the next few days and weeks.

So, check back.

John

Owner

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