Veneer Backer

[Hammer5573]

I'm applying veneer to rounded surface and I'm planning to thicken the veneer with a second layer before application to the MDF substrate. 

1. Is assume that I still need to apply a veneer backer to the opposite side of the MDF ?

2. I can't fit the object inside a vacuum bag because it's too large. Has anybody ever tried ironing the veneer onto the substrate? If so, what type of glue do I use?

[Merlau]

they make some pretty large bags, i have seen stairway sides in a bag. i have seen some paper back veneer put on with contact cement but i am not saying that is the best way to do it.

[wtnhighlander]

Using a hot iron to attach veneer can beaccomplished by painting the mating surfaces with PVA glue and letting it dry. Then place your veneer and apply the hot iron. I've seen it done, but not done it myself, so I can't say how well it holds up.

[wdwerker]

The iron & pva glue trick works well but it needs to be rubbed,down as it cools to prevent any gaps or bubbles . So large surfaces need to be a team effort and there is a definite cap to the size possible. An inside curve needs a curved block to burnish the surface as it cools. Definitely practice before you scale up to the full size project !

[Ronn W]

I am not sure why you would use 2 layers of veneer.

I don't think that you will need to veneer the back of the MDF. If you are worried abouta difference in moisture cause warping, I would consider applying a coat or 2 of you finish to the back or underside of the MDF.

2 hours ago, wtnhighlander said:

Using a hot iron to attach veneer can beaccomplished by painting the mating surfaces with PVA glue and letting it dry. Then place your veneer and apply the hot iron. I've seen it done, but not done it myself, so I can't say how well it holds up.

I have use a hot iron to veneer a curved table apron (about 3" wide).  My veneer was 1/8" thick.  I applied 3 coats of Titebond original glue to each surface letting it dry between coats.  Be aware that the water in the glue will make the veneer curl.  The thinner the veneer the more it curls. That was manageable for my 3" wide aprons but could be a problem required extra hands for a large flat veneer.  BTW the veneered aprons are holding up very well.  Also, the veneer will not stick to the MDF until the heat is applied and starts to cool, so you you have more adjustment than contact cement which has none.  By all means, practice first.

 

 

 

 

 

 

 

 

 

 

 

 

 

md

[wdwerker]

Smart veneer jobs are balanced construction. There should always be a odd number of layers. So the MDF is one layer and the front and back makes it 3 layers total. The unseen side can be cheaper veneer but it should be a similar thickness.

[KilgoreTrout]

If you have an industrial plastics shop, it might be worth checking out.  I found a local shop that sold plastic/fiberglass/carbon layup supplies and bought some disposable vacuum bag material from them.  They sold a film material from a roll, the film was about 24" wide and as long as I wanted it.  I remember it being 'not cheap' but a lot cheaper than the a bag to veneer the 7ft x 18" torsion box I was working on.  The bag material actually worked really well, it was much more elastic than my vinyl bag I typically use.  I ended up holding the bag together with a thick 'gum' like tape, I folded the material over and taped 3 sides, but I don't see why you couldn't use 1 side and tape 4 sides to a substrate assuming you have a good pump.