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Wanted to see if anyone else has experienced this before? Was cutting up a stack of six sheets of basic white melamine today and had a horrible time with it. First ripping them in half on the table saw they kept stalling the blade, as if the material was closing on the cut! Never had this happen before....though I don't use a whole lot of melamine anyway. By the time I had the 6 sheets split the blades teeth were completely glazed with brown gunk....again, never saw that happen before.
But the real problem....the panels moved! The 24"w panels I ripped in 2 pieces are now bowed about 1/32" over 8' of length. The smaller 15"w pieces are bowed a good 1/8"! I know it's not the saw/fence setup because the opposite factory edge has the reverse bow, and it was not there at the beginning!
Anyone else experience their material moving like this before? It's pretty unsettling to be honest. And as I don't have a full sized slider it's going to be a real PITA to straighten the edges....so I'm not a happy camper either! Don't know if it's some kind of low grade product or if something else is causing it?
Happens all the time. Sometimes a lot, sometimes a little, rarely not at all. I have a vertical, so I always rip oversize, then re-rip to straighten one edge and finally rip to final width.
People have said that it is manufacturing stress in the board, but I think that the edges absorb moisture and try to expand and can't till the board is ripped. Btw, the kerf never opens up when the board is ripped. When I drop the top piece on the lower piece (remember I am cutting on a vertical panel saw) there is always a gap in the middle.
I hope this helps...maybe in the future?
I have had it happen the last two times in about the past 6 years and those are the only two times i used melamine...so 100% failure rate for me. Made me want to cuss and throw stuff. Major pita to get everything strait and square. I think its called a banana cut.
I have had the same problem, also occasionally with plywood. Best to be conservative and plan to rip oversize and straighten the rough rips unless the material proves stable enough to do otherwise. Without a saw that can true up a long edge you have a few laborious options:
1. Use a router and straight edge
I see a full size panel saw in your future.
Its possible you have some odd sheets, you didnt tell us the brand, but its not likely. Slow down, rip oversized and correct. Dont blame the melamine. All things considered its usually a pretty stable product. Its only a problem on long pieces( over 50" or so) and frameless cabinets. Cross cutting first can be a great solution as long as you have thought out your cuts well. A riving knife or blade spliter will help a little too. Make sure you are using the correct blade for melamine and that its sharp. I notice an increase in this effect when my blades start to dull. If your blade teeth are loading up that quickly try using a blade cleaner, then spraying a dry coat lube on them.This will help you last a little longer before you have to clean the resin off again.
Thanks for the responses guys, good to know it's not just me! As I said I don't use melamine very often, but I don't remember this happening on the last job about 2 years ago. However that particular batch was a non-stock woodgrain that came directly from Canada, so maybe a better grade? I have no idea what brand this was, I didn't specify when ordering as I didn't think it was necessary. I will bring it up with the rep when he comes by next time though.
Jonathan, what else can I blame if not the melamine....it's moving! I thought the stuff was more stable than this but I guess that's my own ignorance. These are all tall Euro wardrobe cabinets at roughly 87" tall so as bad as it gets I suppose. I couldn't feed any slower, as it was I had to back the sheet out of the saw after cutting about 10" or so and start over as it just wouldn't feed. After the initial rips I replaced the blade with a freshly sharpened blade, (all fairly expensive double sided melamine blades fwiw), and still had problems even on the short crosscuts!
Anyway I used the track saw to straighten the initial edges and then re-ripped on the table saw to get a clean front edge. Ended up spending a good half a day just to get the parts cut for 6 tall wardrobe cabinets.....but I did get them cut!
If your feed rate was as slow as you say and you were binding a fresh blade then there was probably something wrong with the melamine. My melamine is usually made by AmLam or American forest products. I use melamine in both 5/8 and 3/4 all the time and can not recall ever having a tension/warping problem that bad. So yes i guess you could blame the melamine. The only way to know would be to get in touch with your supplier to see what they sold you, then possiblys test a sheet from another brand. The brand is usually stamped on the edge of the sheet
check with your supplier to find out what product/quality they are sending you. 90% of the cabinets we build come with white melamine interiors. We have cut 1000's of sheets over the years both on a cnc and regular table saw, and have never had any issues close to what you have described. Minor bowing maybe, but never so bad it couldn't be dealt with. The majority of white melamine that we use is 5/8" Roseburg Duramine with a particle board core.
Banana Boards!! Talk to Rudy at Colonial Saw in MA and he'll explain the science of hot press laminating melamine and how it affects the stability of sheet goods and what you can do. It may be looking for a different melamine supplier.