Thread: Timber overlay on MDF substrate

If you laminate both sides, you shouldn't have too many worries. If you only laminate one side, there will be tears before bedtime. If you're using an expensive timber on top, you should be able to get away with a cheaper one with similar characteristics on the back. (Don't know what has similar characteristics to Huon though.)
I'd use 1-2mm thickness - gives you room to clean it up and repair any future minor damage.
My glue of choice would be Techniglue epoxy, because it gives you a bit of time to work, but there's also an AV Syntec cross-linked one that gives even more time. Can't remember the number off the top of my head - check out their web site.
That's a big size to laminate - are you going to make up a big vacuum bag? You could make one out of vynil sheet - you can join the sheets with strips of yellow tack to make them airtight.

Good luck - let's see the result.

Thanks for the comments.

I must be mad. Think I'll step away from this and take another approach.

Th problem I have is that there is only one company in Oz that can veneer sheets greater than 1200 wide. Many companies, Laminex included can do 3600 x 1200, but only one (Realwood in Melbourne) have an 1800 mm wide press. Unfortunately, Realwood can't cut to size (the sheets are too big for their tablesaw) accurately. I'd prefer not to have to handle sheets that thick (33mm) or that big or heavy (114Kg each) on my own. Looks like I'll have too.

I think the best course of action is for me to buy in 3600x1800 sheets (145Kg each), cut them down and edge them with solid timber, send them out to Realwood to be veneered, then plane up the edges to remove all the glue that's sequeezed out. That's why I'll need solid edges.

Thanks for the comments.

I must be mad. Think I'll step away from this and take another approach.

Th problem I have is that there is only one company in Oz that can veneer sheets greater than 1200 wide. Many companies, Laminex included can do 3600 x 1200, but only one (Realwood in Melbourne) have an 1800 mm wide press. Unfortunately, Realwood can't cut to size (the sheets are too big for their tablesaw) accurately. I'd prefer not to have to handle sheets that thick (33mm) or that big or heavy (114Kg each) on my own. Looks like I'll have too.

I think the best course of action is for me to buy in 3600x1800 sheets (145Kg each), cut them down and edge them with solid timber, send them out to Realwood to be veneered, then plane up the edges to remove all the glue that's sequeezed out. That's why I'll need solid edges.

Monoman,
you've pretty much answered the question yourself, but I'd suggest that you edge strip in timber after the veneering process. It will look neater as you won't be looking onto the edge of the veneer.

Mick

I've seen some examples of what you're wanting to do by David Marks on the DIY channel on Foxtel - admittedly not on the scale you are talking about - a dining room table, but the principals would still apply.

1. Veneer two sides of the MDF substrate (cheaper wood on the underside).
2. He made the veneer himself by cutting down his stock (say 140 x 35) using a bandsaw to about 3mm (sizes are appox because being an american show they use imperial measures).
3. Run the veneer through a drum sander to get even thickness, and run through table saw to get straight edge.
4. Edge glue the veneer and clamp.
5. Apply the veneer to the substrate - think he clamped again

Have a look at www.diynet.com - Look for show Woodworks and project Display Table -- Burl Veneer Top.

Hope this helps.

I have a similar question that I have been meaning to ask for weeks.

I would like to do a computer desk .... basically just a rectangle lets say 2000x900mm ...... I have some silver wattle about 19mm rough sawn. I would like a chunky top about 40mm, can I glue the wattle directly onto a 19mm MDF base and then apply solid edges? Same problems apply as above .... what about movement etc. Would it be better to have the edge strips attached to the mdf and the top sits in without being fixed?

thats a lot of board room table with a lot of greedy directors and board members in the one place at one time. Might be an idea to imbed steel spikes under the veneer which can shoot out and impale if the share prices drop to low.

What I have done with large tops like this is to incorporate a solid timber strip in the middle of the top thus allowing the top to be made in 2 pieces and then joined together on either side of the solid timber strip which could be the same species as the veneer or a contrasting timber . Good luck . Post some pictures when you have finished

Originally Posted by Sir Stinkalot

... can I glue the wattle directly onto a 19mm MDF base and then apply solid edges? Same problems apply as above .... what about movement etc. Would it be better to have the edge strips attached to the mdf and the top sits in without being fixed?

Stinky,

Same problem. You will find (as I have) that the wattle will cup or warp over time, enough to either lift off the substrate altogether or warp the whole top.

Best off either cutting it down to laminate in thin strips (both sides), or using it for something else and buying veneered boards.

I've seem, and worked on many antique pieces which have been veneered on one face only, and they have not warped. Most of the veneered pieces where help captive by the carcase. Nevertheless, it's not something I would consider doing. Actually, I've heard of boxmakers veneering the completed box, so must only be on the outside faces.

Originally, I thought that id I used a thick timber overlay (around 10mm), I could get away without doing the same on the reverse side. I was hoping the that the 32mm MDF substrate would not easily be warped by the 10mm overlay. I could always laminate some thin MDF of the reverse to counterbalance the cupping.

I don't have a veneer press or vac bag big enough, so was thinking of using the 3 other tabletops (at 710kg/m2, a 2700 x 1700 x 32mm MDF sheet weighs in at 107kg) as a press.

Originally Posted by Bunyip

Stinky,

Same problem. You will find (as I have) that the wattle will cup or warp over time, enough to either lift off the substrate altogether or warp the whole top.

Best off either cutting it down to laminate in thin strips (both sides), or using it for something else and buying veneered boards.

Bunyip .... the Wayttle is 10 year old air dried stored under cover ... is cupping really going to be an issue? I have tried the same with my current desk ..... recycled jarrah floor boards over 19mm MDF with only slight movement but no real large cracks opening up.

Actually I was wondering about that to. I have a lot thin pieces left over from slabs I have dried and resawn. I have intended to use them to cover MDF to make table tops and panels.

I had intended to use hide glue. I think that there is a tool called a veneering hammer which is not really a hammer at all. What I hoped would work was to use the hide glue which has a quick tack time and the veenering hammer or a tool like it to place the timber onto the MDF without using a vacumm press.

Will it work? :confused:

Originally Posted by chook

I had intended to use hide glue. I think that there is a tool called a veneering hammer which is not really a hammer at all. What I hoped would work was to use the hide glue which has a quick tack time and the veenering hammer or a tool like it to place the timber onto the MDF without using a vacumm press.

Will it work? :confused:

Hide glue does work. It's been around for ever. My dad taught me this for of veneering over 30 years ago. Don't think it'll work on thicker than normal veneer as hammer veneering requires ironing on the veneer an therefore heating through the veneer to the glue underneath. It's also very messy and doesn't smell to good either.

You'll need the following tools:

A heated glue pot. ($250+ I'd guess)
A electric clothes-tytpe iron. ($5 at the salvos)
A veneer hammer. ($30)

A veneer hammer looks like a hammer, but it's actually used to rub the veneer down and push out air bubbles. You don't beat the veneer with it.

Veneering this way is considerably different from using a veneer press (vac or mechanical). Firstly, when pressing veneers under pressure, the first thing to do is to edge join the veneer into a sheet slightly larger than the substrate. This is normally done by taping the veneer leaves together. Glue is then applied to the substrate only, the veneer is then positioned, and the whole thing is clamped under pressure until the glue has set.

When hammer veneering, veneer leaves are glued on one at a time. Each subsequent leaf must be glued on before the previous has set because the leaves are overlapped by 10mm or so. A straight-edge is then laid along the joint and both veneers are slided through. You then need to lift the edge of the veneer to remove the trapped off-cut. You have to work fast, and methodically until the entire surface is done.

I haven't used hide glue, or hammer veneered in years now. I would be very cautious of attempting any task bigger than a single sheet of veneer.

My advice is if you want to veneer, get a press big enough to handle the job and use modern glues. As for the type of press, seriously look at a vac press. They're way cheaper than a mechanical press, and they take up little space when not required.

Hope this helped.

Chook, isn't the idea of the veneering hammer that it applies localised pressure to the venner when gluing, sort of a squeegee (sp?) action.

If this is right the veneer would need to be thinnish, otherwise the relative stiffness of it would spread the pressure applied and possibly not have the desired result.

Just speculating tho'...............good luck.............Sean