# MDF or Baltic Birch for table tops and jigs?



## JPM80 (Jan 17, 2010)

Title pretty much says it all. Just wanted some feedback/opinions before I get started on my project.


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## Tisdai (Aug 29, 2010)

MDF is the best way i would say.

Dave


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## Cassandra (Mar 15, 2006)

Hi Jesse:

I agree with Dave. MDF is the best way. When you make items with MDF, remember to seal the MDF against moisture. Sealing can be any of the usual techniques, such as varnish, shellac, paint, wax, laminate, whatever.

Cassandra


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## harrysin (Jan 15, 2007)

So far as table tops are concerned, I'm sure that my wife wouldn't have a dining room table made from MDF, UNLESS it was professionally spray painted with a wood finish. As for jigs and templates, that's different, MDF is my material of choice, it's cheap and easy to work with.


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## Tisdai (Aug 29, 2010)

I was refering to a router table top as the core Harry not a dining table lol


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## andersonec (Jan 12, 2010)

*Table top*

A little late with my reply but here goes anyway. I tried laminating 3/4 MDF for a table top three times, yes three, and every time the stuff warped. Tried weighting it down with a serious amount of weight but still it moved. Next time it's definitely going to be ply, more expensive but not if you have to do it four times before it stays flat.


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## RJM (Apr 11, 2010)

andersonec said:


> A little late with my reply but here goes anyway. I tried laminating 3/4 MDF for a table top three times, yes three, and every time the stuff warped. Tried weighting it down with a serious amount of weight but still it moved. Next time it's definitely going to be ply, more expensive but not if you have to do it four times before it stays flat.


 
That's interesting. What were you laminating it with? What glue did you use.

Often, MDF tops are double thick (1-1/2" total) or backed up with plywood.


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## Tisdai (Aug 29, 2010)

I use contact adhesive either the spray on, or spreading it on with a spatula if using it out of a tin. I have allways used a roller to roll over the laminate and then used a scrap board arround the same size and clamped that on top just to be sure, never had a problem doing it that way.

Dave


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## BigJimAK (Mar 13, 2009)

I've used solvent-based contact cement for MDF-MDF and MDF-Formica gluing.. wouked great..


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## AxlMyk (Jun 13, 2006)

andersonec said:


> A little late with my reply but here goes anyway. I tried laminating 3/4 MDF for a table top three times, yes three, and every time the stuff warped. Tried weighting it down with a serious amount of weight but still it moved. Next time it's definitely going to be ply, more expensive but not if you have to do it four times before it stays flat.


There's a trick to it. You glue the convex sides together. )( That way the warp is cancelled out, and you get a dead flat table.

I use MDF for router tables and SOME jigs. If there are going to be screws in edges, I'll use BB ply.


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## bobj3 (Jan 17, 2006)

Hi

You can buy MDF stock that is 1 1/2" thick, they use it for some desk sets but not from HD/Lowes, stop by a cabinet shop and ask them to cut you a chunk off or maybe a cut off they have on hand..

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## Quillman (Aug 16, 2010)

MDF pretty good for passive surfaces (table tops, vertical panels etc) but not great for jigs.
Why? Because jigs need toggles & other clamps to hold the work. Moreover, jigs should be accurate & precise. MDF can't stand the forces of the lightest toggles; small ones are at least 200 pounds and pretzel MDF. Whence cupped (under the load of a clamp or the sudden change in humidity) & mishappen they're no longer accurate. Flatness is criitical with a jig. Cut depths vary, the jig rocks & rolls, moreover there may be some risk to the operator. The same holds for ply.
What then? Aluminum. It can stand the clamp stresses and has no problem with its environment (Temp., humidity or pressure, even works in outer space).


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## bobj3 (Jan 17, 2006)

Hi 

I will agree that Alum is the best if you can live with the black marks that the Alum. likes to leave behind, you can rub it with your finger and it will be black most of the time, it's likes to weep on almost everything BUT most don't have the tools (equipment) to rework it..or just to cut it..some say just use your band saw but to clean up the edges is tricky,,at best.
I use MDF and it works very well for the home shop jig maker and I do make many jigs, I use a lot of tee nuts that gives a good way to take on the force from just about any hold/camp down device..

But just my cents.. 

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Quillman said:


> MDF pretty good for passive surfaces (table tops, vertical panels etc) but not great for jigs.
> Why? Because jigs need toggles & other clamps to hold the work. Moreover, jigs should be accurate & precise. MDF can't stand the forces of the lightest toggles; small ones are at least 200 pounds and pretzel MDF. Whence cupped (under the load of a clamp or the sudden change in humidity) & mishappen they're no longer accurate. Flatness is criitical with a jig. Cut depths vary, the jig rocks & rolls, moreover there may be some risk to the operator. The same holds for ply.
> What then? Aluminum. It can stand the clamp stresses and has no problem with its environment (Temp., humidity or pressure, even works in outer space).


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## Howie (Sep 12, 2010)

andersonec said:


> A little late with my reply but here goes anyway. I tried laminating 3/4 MDF for a table top three times, yes three, and every time the stuff warped. Tried weighting it down with a serious amount of weight but still it moved. Next time it's definitely going to be ply, more expensive but not if you have to do it four times before it stays flat.


Was your clamping surface flat? Just wondering.:bad:


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## Cassandra (Mar 15, 2006)

bobj3 said:


> Hi
> 
> I will agree that Alum is the best if you can live with the black marks that the Alum. likes to leave behind, you can rub it with your finger and it will be black most of the time, it's likes to weep on almost everything BUT most don't have the tools (equipment) to rework it..or just to cut it..some say just use your band saw but to clean up the edges is tricky,,at best.
> I use MDF and it works very well for the home shop jig maker and I do make many jigs, I use a lot of tee nuts that gives a good way to take on the force from just about any hold/camp down device..
> ...


Hey Bob:

Wondering what your opinion is on an idea. How about wrapping an aluminum top in MDF (say 1/4") and hardwood edging? One would get the benefit of aluminum without that nasty trait.

Cassandra


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## bobj3 (Jan 17, 2006)

Hi 

Right on 
The only way to get away from the nasty trait of Alum.is cover the top with some 1/4" thick MDF in that way the drop in plate is just the right height the norm..most of the plates are 1/4" thick or have a 1/4" thick lip on them like the HF plate for just one of them...some will say just coat the Alum. or put some spray finish on it but it will not stick to Alum. the norm..that's why they anodize Alum. to get it stick and to get rid of the nasty marks from Alum., but it will lift in time also.. 


http://www.harborfreight.com/router-table-plate-94331.html
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Cassandra said:


> Hey Bob:
> 
> Wondering what your opinion is on an idea. How about wrapping an aluminum top in MDF (say 1/4") and hardwood edging? One would get the benefit of aluminum without that nasty trait.
> 
> Cassandra


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## Ralph Barker (Dec 15, 2008)

JPM80 said:


> Title pretty much says it all. Just wanted some feedback/opinions before I get started on my project.


FWIW, I'm finishing a new router table for which I laminated two pieces of 3/4" phenolic ply (using contact cement - most other glues don't stick to it). I've had MDF sag over time when it's under constant weight, so I figured a BenchDog lift and a PC 7518 might be too much for it in the long run. 

I also like phenolic ply for some jigs, Baltic Birch ply for some, and MDF for others. The selection depends on what the jig is for.


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## andersonec (Jan 12, 2010)

RJM60 said:


> That's interesting. What were you laminating it with? What glue did you use.
> 
> Often, MDF tops are double thick (1-1/2" total) or backed up with plywood.


Sorry for the delay (internet router problems) I was gluing the MDF with contact adhesive. I made sure the sheet I purchased was from well down in the pile so it was flat to start with. The problem I find with MDF is that when you apply the glue to one side, the effect of dampening the one side causes that side to expand slightly, common sense says that if you then stick these expanded sides together they should cancel each other out, no such luck. The boards were placed on bearers which were on the hallway floor so they were flat, and to get some pressure in the middle of the boards (where the hole for the insert is to be routed out) I placed twelve building blocks on the board, my clamps would only apply pressure to the edges. 
Personally I would stick with ply for a number of reasons, 
1, Pva glue can be used to laminate it thereby giving you more clamping set up time. mdf soaks it up like a sponge. 
2, It is more stable and not so prone to movement due to moisture, 
3, Which brings me on to another point, spill some water onto mdf and it is destroyed. 
4, Ply will hold screws better. 
5, Ply will take a finish better should you wish to apply one.
6, The edges of your mdf are vey fragile and will have to have some sort of edging applied for protection.
7, I know this is only a small point but when routing mdf the dust can be very annoying.
etc. etc.


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## bobj3 (Jan 17, 2006)

Hi Guys

I have a MDF top for last 5 years and it is still flat and true and you don't need any edging for MDF, just a nice round over will do the job just fine  but it's true I don't take it outside in the rain  but it has a nice wax job just to make sure  plus you don't need to hide the nasty look of plywood with some edging.


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## JPM80 (Jan 17, 2010)

thanx for all the replies.

Sounds to me like plywood is the way to go. Holds screws better, easier to glue up. Hopefully, I can get started soon. Seems everytime I have a little extra mullah something comes up(water heater, vacuum cleaner, car brakes).

Perhaps I'll have enough posts to show some pics.


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## andersonec (Jan 12, 2010)

Hi Bob, I figure a good coat of wax or some such protection is paramount really and to be frank I suppose it's all down to a matter of preference. Baltic/Birch ply edge can be quite attractive in it's own right though, they used to make furniture with the edge on show


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## Mike (Nov 22, 2004)

The most important thing has not been mentioned. What ever choice you make for your table top will work. Get started and enjoy!


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## bobj3 (Jan 17, 2006)

Hi Andy

I don't recall seeing Any plywood that's attractive, it's still just plywood  the Baltic/Birch ply. has less voids but it's plywood..it's like seeing joints on furniture just not attractive  it makes me thing the builder just didn't have the money to go to that extra step and cover that stuff up..with some real wood..

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andersonec said:


> Hi Bob, I figure a good coat of wax or some such protection is paramount really and to be frank I suppose it's all down to a matter of preference. Baltic/Birch ply edge can be quite attractive in it's own right though, they used to make furniture with the edge on show


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## Cassandra (Mar 15, 2006)

Hi Bob:

Different strokes for different folks.

I'm with Andy on the issue of not needing to hide the edges of BB plywood. I've seen furniture in the store with this idea. I like.

Cassandra


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## Ralph Barker (Dec 15, 2008)

*ply as decoration*

Does a tiger cover its laminations (stripes) with "real skin"?


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## bobj3 (Jan 17, 2006)

hahahahahahahahahahaha LOL LOL ,if he was made of wood maybe he would  no one likes to look cheap..but than aging I have seen some that like that look.." cheap "


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Ralph Barker said:


> Does a tiger cover its laminations (stripes) with "real skin"?


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## Mike (Nov 22, 2004)

Actually Ralph the tigers skin is striped too.


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## Ralph Barker (Dec 15, 2008)

Mike said:


> Actually Ralph the tigers skin is striped too.


That's what I've heard, Mike. But, I lack the gumption to personally verify the fact. Rubbing a tiger the wrong way doesn't sound like a good idea.


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## Jim Rimmer (Oct 21, 2010)

andersonec said:


> A little late with my reply but here goes anyway. I tried laminating 3/4 MDF for a table top three times, yes three, and every time the stuff warped. Tried weighting it down with a serious amount of weight but still it moved. Next time it's definitely going to be ply, more expensive but not if you have to do it four times before it stays flat.


Did it move immediately or after in use for a while? My reason for asking is that I have read other places that you need to laminate both sides or moisture can enter the MDF from the bottom and cause swelling, etc. I guess you would need to seal the edges as well.


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## andersonec (Jan 12, 2010)

Jim Rimmer said:


> Did it move immediately or after in use for a while? My reason for asking is that I have read other places that you need to laminate both sides or moisture can enter the MDF from the bottom and cause swelling, etc. I guess you would need to seal the edges as well.


When I say 'Laminate' I meant that I was trying to laminate two pieces of 3/4 MDF together, the stuff warped every time and when you have two pieces of 3/4 stuck together it's almost impossible to flatten, next time I would fix the first layer down to the table THEN glue the top layer down, weights in the centre and clamps around the edge, that way you could screw down through the bottom layer into the table frame paying careful attention to the placement of your screws, thereby making the first layer stiff and flat ready for the top layer. Any laminate cover you wish to use can then be applied without fear of movement.

Andy


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## Saxman (Nov 1, 2010)

Hi Folks,
I know another issue is there are many vendors who advertise MDF, but in fact the product is not true. Many of the big box stores sell MDF that is porous and absorbs moisture quite easily. The comment about getting your MDF at a cabinet shop is something right on the money. They always have the true MDF. 

I also learned if you make jigs and tops out of MDF, putting a sheet laminate finish on both sides (IE Formica type) makes the product perform better when it comes to things like mounting tracks, toggles and so on.


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## Pete_Judd (Oct 19, 2010)

I use mdf and hdf all the time in the shop without problems. The top of my outfeed table for the table saw is two sheets of 3/4 inch mdf and no warping ever. And I live in a moist area of the country. Maybe, the glue is reacting with the glue in the MDF?


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