Panel Goods and Cutter Life
A search for melamine-faced MDF leads to a long discussion on the way different types of panel materials wear out tools. February 14, 2006
Question
I am searching for a place where I can purchase melamine coated MDF, thickness 1.25". Local lumberyards and home centers have uncoated MDF, or melamine coated chipboard, but not melamine coated MDF. The local MDF manufacturer might be able to do a run of melamine coating (thermofuse process), but the expense is prohibitive. Anybody know of other options?
Forum Responses
(WOODnetWORK Forum)
From contributor F:
I looked into the same thing because I like the fact that MDF is very gentle on saw blades and other tooling, as compared to particleboard core, which is very hard on tooling. My cabinet materials supplier can bring it in for me, but I would have to buy full units and it runs about 6 dollars a sheet more than particleboard core.
From contributor F:
Reread your post and depending on how expensive your 1.25" quote was, you could make your own "two side" by purchasing vertical grade laminate and laying up your full sheets with contact cement. Plastic laminate is melamine, it's just a lot thicker. MDF is available in a lot of odd sized thicknesses and you may even be able to net 1.25" with an available thickness of MDF and two sheets of vertical grade laminate.
From contributor M:
You might want to check your research. My experience and past reading in these posts has always told me that MDF is much, much more abrasive and rough on your saw blades and router bits. Additionally, particleboard core material holds a screw and/or staple much more effectively than MDF core material. Take a sheet of 3/4" MDF and drive a screw into the edge without pre-drilling. Then do the same with particleboard. Also, if you need to butt joint something, once the melamine paper is removed (say a 1/8" deep dado or blind dado), a glue joint will be much stronger if you are using particleboard core material instead of MDF. 1 sheet at $6 more, not a big deal, but a whole or multiple bunks, you might want to rethink your game plan.
From contributor F:
I used to run a CNC router with a single flute carbide bit for a cutter. I would routinely cut parts from 30 or more sheets of the same material daily. It became very clear what materials wore the carbide bits out the fastest. In this order, with the materials I was cutting from hardest on the tool to least hard on the tool:
1: Plywood
2: Particleboard
3: Solid wood
4: MDF
If you know how to sharpen, take a sharp chisel to a scrap of MDF and make some slices, then try some particleboard. You will see that the MDF is much softer. You are right about the screw holding properties. MDF does, however, make a very strong glue joint from the face or edge. Glue some up and try to break the joint.
From contributor A:
Yes, most people think cutting MDF is easier because of how it can be cut with a chisel, how it sounds when routing, etc. The reality is that MDF is very abrasive and will wear carbide, and even diamond tooling, faster that particleboard. I have seen this with my own experience. Ask any tooling expert and they will agree.
My experience has been with particleboard and MDF, routing up to 200 sheets (or more) per day. Even if MDF saved you money on tooling... Would it save $6.00 per sheet? At 30 sheets per day, that would equal $180 per day. Maybe you should try using better tooling. Straight shears don't give as good a quality on a CNC router as a compression spiral would.
From contributor D:
We crossed paths about the aggressiveness of MDF awhile back (zero clearance TS inserts). You might want to pose your MDF beliefs on the Solid Wood Machining Forum. Dave Rankin will take you to task. Most people are under the assumption that harder objects wear out cutters faster than softer ones. This is usually true. However, in the case of MDF, it is a pretty soft material, but due to it's glue content, it is very abrasive. You mention plywood as a dulling product. The gluelines are very destructive. I would assume by its weight (90lbs for a 3/4" sheet), MDF has got plenty of glue. If you cut a few dozen sheets of MDF, you can actually see it abrading the carbide rather than just dulling it. I only use MDF for painted raised panels. Believe me, it wears out the shaper cutters quick and I always rough the bevel on the TS first.
From contributor F:
I surrender. I would like to see some hard facts, but I can swear from what I remember seeing that my CNC tooling stayed sharper longer on MDF than on particleboard. I am convinced that plywood is the worst - might be a combination of the glue and the end grain. I remember buying my first saw blade from an old saw sharpener many years ago and I remember him commenting on the particleboard being sold at the time and how the quality of it had changed and they were letting metal and glass and sand and rocks, etc. get into the mix (cut some in dim light and watch the sparks fly). There must be something to what you guys believe about MDF and PB, but I know I can joint the edge of MDF on my jointer with little worry, but one pass on the edge of PB will hose the knives.
From contributor A:
What kind of PB are you running? Perhaps you are cutting a poor grade. It is true that you may see variations in particleboard quality that will affect your cutter life. Perhaps you need to find better board?
From contributor F:
Around here they call it "core pine" or "pine core". When I use melamine, I buy the more expensive one that my dealer offers, called "International".
From contributor R:
In the 18 years I have been a cabinetmaker, I have always been under the belief that particleboard and MDF both contain some degree of metal, as both contain recycled material from reject and screwed up orders of doors and drawers, cabinets, old pallets, etc., which contain fasteners of all types that are never filtered out. Don't have a source for this other than my sales reps.
From contributor F:
I can't really say one way or the other about the quantity of impurities in MDF and PB. I think, however, that since MDF is made from "wood flour," the debris is smaller and more diffuse. In particleboard, you can find whole metal bolts sometimes. Anyway, I would be interested in some science about which is harder on tooling. I only know what I think I see with my own eyes in my own shop.
From contributor D:
Who runs PB or MDF through his planer or jointer on a regular basis? A jointer is used to straighten boards, not to dull high speed steel knives.
From contributor M:
All the major players - Uniboard, Panolam, Tafisa and Flakeboard - should be able to provide the 1.25" MDF core material. I'm sure there are minimums, but it is available.
From contributor R:
I just received the new Redbook from 'Wood & Wood Products' magazine. They are an excellent source for finding a supplier for the product you're looking for. If you don't subscribe, you should. View the chapters for panel products and laminating and veneering.
From contributor F:
I agree that a host of thicknesses are available in MDF, as I stated in a previous post. And I don't personally know anyone who joints or planes MDF and PB on a fulltime basis. I have worked in many branches of woodworking, and there are as many ways to work with wood as there are people to do it. I am personally fond of accuracy in tool and jig/fixture making, and when I use MDF in a jig (as you know, I prefer MDF over PB), I will straighten the edge of a piece of MDF on my jointer when I think it is necessary to do so.
From Gene Wengert, forum technical advisor:
There is the chance that any wood product can contain non-wood materials (in addition to adhesive). The manufacturer will run an ash test (a small piece is burned and the metal and sand, etc. will not burn, while the wood burns 100%). The percentage of ash indicated relates to the problem of abrasive wear on the tools. This non-wood ash can arise from sand accumulated in logging or where the chips are stored. Ask your supplier for ash test results. Obviously, the amount of ash varies minute to minute, depending on the source of wood.
Most MDF is made so that any foreign matter falls out, so MDF ash content is typically quite low. If you saw how they make these products, you would find out that cans, bolts, wrenches, etc. cannot get into the product.
The real issue here is that the tooth can either be worn away by abrasion or can be deteriorated by heat and then more easily worn away. So, the density of the material is critical when talking about wear. So is the tooth clearance (both side clearance and top clearance for saw blades). The tooth must have room to pass through the saw cut without rubbing and heating. It is not at all uncommon to find that side dressing (sharpening the sides of a tooth) is not done well.
Further, if the saw does not have enough power, then the feed must be slowed with denser material. This means more rubbing and more heating. Be aggressive. Sometimes a sawblade has too many teeth for the material it is cutting, which means small cuts per tooth and lots of rubbing. As the material changes, we also need to change the blade design.
From Gene Wengert, forum technical advisor:
I neglected to mention amount of adhesive in the panel. The amount varies. More adhesive makes the panel stronger, but is more abrasive. Check the specs on the panel for adhesive content.
From contributor A:
What do you mean when you say "be aggressive"?
From contributor F:
What Gene said about density and heat seems to explain what I saw when machining large quantities of the same type of sheet goods. The particleboard is denser by far than the soft MDF and the cutter gets hotter and wears out faster. For the order of materials that are hardest on the tooling, I still say:
1 - Plywood
2 - P.B.
3 - Solid
4 - MDF
From Gene Wengert, forum technical advisor:
We usually find that a saw blade is designed to take a certain cut with each tooth... perhaps each tooth will remove 0.05", so when 100 teeth have gone through the piece, you have sawn 5". This bite should be a number you can find. Alternatively, the finer the sawdust, the less aggressive you are. So, watch the dustiness of the sawdust.
From contributor S:
I'm of the school that says MDF is abrasive as hell, but I trust contributor F when he says he's run enough panels through the CNC machine to see for himself. A thought occurred to me as I read the posts that maybe everyone is right. Maybe MDF is truly very abrasive and rough on carbide tips, but that contributor F's CNC machine is powerful enough to push a dull bit through the relatively soft material, making it seem like the bit is still sharp. Wouldn't that explanation fit everyone's observations?
From Gene Wengert, forum technical advisor:
All MDF is not the same. Density and adhesive content vary, which affects abrasiveness. Further, feed rate affects wear, as stated.
From contributor F:
While it is true that my CNC was powerful enough to cut material even after the carbide fell off of the bit, my beliefs about which materials wear a tool faster is based on what the bits looked like after running quantities of the various sheet goods. Plywood and particleboard would put nicks and even leave chunks of carbide missing, as well as burn the bits in a shorter timeframe than MDF. Just for the record, the MDF was always made by Plum Creek.
From contributor V:
"If you saw how they make these products, you would find out that cans, bolts, wrenches, etc. cannot get into the product."
I have seen MDF made and in theory would agree with you that the chance is slim, but we cut a sheet of MDF about two weeks ago that had a piece of flattened out 3/4" conduit in it. It destroyed the blade. It had to have fallen into the dough off the line prior to pressing. I will dig around for a picture on Monday.
From contributor F:
It's actually kind of humorous that when I first started woodworking, I would drive out to the countryside and meet backwoods sawyers to buy rough sawn boards. These guys would often have stories of all the foreign objects that they have found in the logs that they have sawn. There was a guy named Moses near San Jose, Ca. that had a sort of museum with an old tricycle in the butt of a tree, pistols in the crotches, as well as lots of horseshoes and other assorted debris. These days I have seen and also heard about all the treasure that is to be found in particleboard and MDF. We have found whole bolts in particleboard and in MDF as well.
