Dry-fit pieces of table through a planer?

[hugh lonner]

Hopefully it isn't a breach of board etiquite to ask this question twice. I asked it buried inside of another thread and never got a response, so I thought perhaps I might have better luck if it were asked in a thread for which it was the topic and not an aside inside a different thread...

I'm building a tabletop and the pieces are close to flush with biscuits dryfitted in, but not perfect. Often people recommend gluing up pieces that fit through the planer, running them through and then gluing up the three or so pieces to get a single table top with only 2 seams that might need attention. Can I improve on this by sending the pieces through with biscuits, but no glue then taking them apart, reassembling them in a different way and sending the new pieces through taking light cuts until every seam has passed through the planer a couple times (so perhaps do board 1 and 2, then 2 and 3, then 3 and 4, ... then repeat)?

thanks,

Hugh

[Glen Butler]

I could work, but the problem I see is that when one piece is high to the joint then there is a void under it. If you are only doing two of the four then you could end up with a wavy table top. Also, it seems that your joints can't be all that close if you need to take more than one pass. When I have something I can't run I go to a local planing mill with better equipment than myself. That is what I recommend you do. Glue it up at take it to someone who has a wide belt sander. Then you save yourself all the sanding time too. You should be looking at no more than $10 to get it done. For me the price per foot gets considerably better the more feet I have.

[Faust M. Ruggiero]

Finish build your table then hand plane or belt sand the surface level. If you attempt to run two boards through the planer, they will tip one way or the other causing your next jointed surface to be out of square and both pieces thinner than the next board you will glue up. By the way, the biscuits were not necessary since you are gluing long grain to long grain. They don't even work to help align the boards since they are a loose fit until they swell. Dowels would have been a better choice for alignment. Better yet, use cauls across the boards to hold them into perfect alignment.
fmr

[Paul Murphy]

Something to keep in mind concerning biscuits: they are compressed before glue-up, and so are loose enough that they will allow movement. The joint isn't really tight until moisture in the glue swells them to to fill the joint. I would not bother working the "glue-line" until it has been glued.

In my personal experience with an old PC biscuit joiner, it really isn't all that great at yielding a flush surface. Perhaps I could setup the tool better, but honestly I prefer to glue tabletops without biscuits anymore. I glue 2 boards and tap the joints until flush, 15 minutes later I add another board, and repeat every 15 minutes until the tabletop is at full width. It's kind of a pay me now or pay me later process...I spend more time during glue-up, but less time working glue-lines after glue-up. I think I actually save time in the end, and don't have to worry about exposing a biscuit when crosscutting the tabletop.

I don't live near anyone with a wide belt sander, so I glue carefully, and get rid of the squeezeout while it is still rubbery. After waiting a day or two I flush the glue-lines with a cabinet scraper. I don't have to sand as much as I used to, that is one more positive aspect

[Chip Lindley]

Another problem with trying to plane your table top is, if grain reverses direction (for a more pleasing look) you run the risk of tear-out which will ruin your surface.

If boards are already planed to same thickness, further planing will only make the top thinner. And, you must take a pass on both sides to equalize tensions in the boards.

If you have access to a wide belt sander, go for it! There is no substitute for a flat table top surface. It's worth what you will pay a shop to run it through for you.

Otherwise, plan on finish sanding the top once glued up. A ROS takes off lots of wood in a hurry with great control. Start with 60g discs, and work your way down to 120g. You can work on high spots and blend in areas. A few hours work, and you have a very nice, flat table top!

[Fred Perreault]

I build cutting boards once in a while. When I assembled my first laminated board, the pieces did not make a perfectly flat surface, so I ran the glued up board through the 15" planer. Being different woods, and with varying gain orientation, there was some tearout. So, a couple of passes later, the tearout became chipout, and much deeper. I quickly learned that the planer is not the best way to resolve mis-aligned layup. Take your time during layup, and use hand tools and a good straightedge, or find a local wide belt surface sander for the levelling. It may be tedious, but you will have better control and feel good about it in the end.
Your eyes and your fingertips will tell you a lot.

[Ken Shoemaker]

I recently took a 23" cherry board, that I intend using for a coffee table, to a local cabinet shop with a 58" wide belt. They quoted a great price and ultimately did not charge me for running it through.

Unfortunately, those guys have alot of time on their hands these days. So you might as well take advantage of it...

Ken

[Terry Welty]

+1 Glen... large sander is the way to go...

[Keith Outten]

Find someone in your area with a CNC Router. The entire table top can be machined flat in just a few minutes.
.

[hugh lonner]

Thanks to all for the good advice. I did follow it and glued up two pieces, ran them through and ran the third through the planer and now have to join those three pieces. I found a local shop that said they could flatten it easily and cheaply if it needs it. I was surprised how little planing the joined boards needed.

As I did it I realized one more reason why my dry-fit suggestion was a terrible idea (and I'm glad I didn't do it) as I was running the wood through the planer. The biscuits are referenced off of the top, but the planer moves the tops and probably wouldn't move them all exactly equally, so then the biscuits instead of helping keep level seams would do the opposite and ensure bad seams.