Friday 12 April 2013

Construction of veneer substrate press cauls and veneer cleaning jigs


Some information on Veneer cauls that I gathered from Collins complete woodworker's manual that I bought. (sorry about the blurred end section cant get a proper scan from my scanner)

To speed things up with my veneering I could do the face veneer and backing veneer both at the same time. I have decided to do each at different times. This is for a couple of reasons.

1. the glue I'm using I have a limited time to work in.

2. Some of the figured maple veneer is buckled and need some extra work to it.

3. My work space is limited especially with all the veneer laid out on flat sheets. Id rather work on one of the veneers first than the next. There are bricks on the veneers ( on a top caul that is over the veneers ) to keep them flat and I don't have the time to jump in between each veneer stacks.

4. Have not done glue testings on the figured maple yet, may be using a different glue with it compared to the wenge where I need to use a polyurethane.



I bought 2 2400mm by 1200mm MDF sheets that were 18mm thick from Bunnings Ware House.

Now I hate using MDF and wont use it for parts for projects. But for jigs, templates and other things like cauls ill just use it since its cheap.

I was cutting out the cauls to press the veneer onto the substrate parts. Since the saw in my work shop is too small to cut really large sheets like this I have to cut the panels down to smaller sections with the festool circular saw first on the cutting station.


When the parts got to smaller sizes I was able to get my mum to help by having her hold the offcut section to prevent it from falling to the ground when finishing off the cut. Also this prevents splitting when the saw exits the exit cut.


The friction matting and the clamps work really well for this to hold down the part while cutting.



Tracing out the front door flap to get the shape of it onto the panels for the cauls. The back doors would share the same cauls as the front door flaps. Now for the doors there would be a top caul, a middle caul and a top caul. This is so I can press to doors at once instead of two.

The cauls would not be the exact size of the door about 10mm offset all round. The back door is smaller than the front door flaps any way this was more for the front door flap sizing.


Using the top carcass substrate panel as a template to transfer the shape to the MDF to make the cauls. The top carcass would share the same cauls as the Ikebana base shelf and the top drawer base panel. I just measured the largest one out of the 3 to work out the right offset size for the cauls. There is only a top and bottom caul for this.

The cabinet base and top substrate had a different sized caul a bit larger. This only had a top and bottom caul.


Cutting off the offcut sections for the cauls.


Since one is cut can use as a template to mark out the next one.



Since I would be handling the cauls heaps I decided to sanded the edges down so they would not be so sharp.


Marked all the cauls and what parts were going to be referenced to them. This is so I wouldn't use the wrong caul for the the wrong job.


Some of the cauls made and ready to be used to press the veneer to the substrate.



I also made cauls for the drawer bases. Now drawer base lids would also share the same cauls as these as well. There is a top caul, middle caul and bottom caul for this set up. This is so I could press up two piece at once.


Cutting drawer base/ lid cauls on saw cutting station.


Sanding edges with orbital sander.


With the left over sections from the sheets of MDF I wanted to make some sanding jigs. What these jigs would do is that they would hold the parts down while I would be sanding them after they have been veneered. The jigs would have fence stops on them so the parts could rest up against and would have that same friction material on them like the saw bench. This would prevent the parts from sliding around and would also protect the edges from being scratched.

These jigs would also prevent having to clamp down the parts or hold the part with one hand while trying to sand it. I could clamp the jigs down to the work bench with F clamps or secure them against the dog tail stops with the dog tail fence.

A few jigs needed to be made to accommodate the different shaped parts.



Needed to make some of the fences for the jigs with some scrap black wood lying in the work shop.


Cut down the parts and thicknessed them down to the specific sizes on the multi combination machine. The fences needed to be below 16mm. I made them to 14mm. This is because I didn't want the fences higher than the parts this would prevent me from sanding the parts properly as the sander would always hit the fence.

I sanded the edges on the fences and pre drilled them before screwing to the MDF jig base. I applied some wood working glue and used clamps to secure it to the base while I screwed the screws into the fences to attach them to the MDF jig bases.



Same principal as above just a different jig for other shaped parts.




To attach the friction material to the base of the sanding jigs I used the same double sided tape I used for the saw router station.


Cutting the friction material to size and placing down on the base of the sanding jig. I had to buy some more of the friction material since I ran out from the last project.


Jig ready to use.


Cutting and applying the material to the next sanding jig. This sanding jig will be mainly used for the large square panels. Could also use this to sand the legs for the cabinet as well.


Jig ready to use.



I decided to make another sanding jig as well. This jig had two different sanding fences. One angled to suit the weird shape of the drawer bases and lids. At the other end to secure smaller square pieces like the drawer fronts, backs and sides.


Same principal as before.



Set up one.


Set up two.





Made some cauls for the drawer fronts and sides. They would share the same cauls. Top caul, middle caul and bottom caul. The pressing for these I probably wont need to press them up at work I reckon I could press them up in my work shop with F- Clamps just making sure to get the right clamping pressure.


Was able to get some more double sided tape to finish off this sanding jig.



Placed down the friction material which will secure the parts and prevent them from slipping when using the cabinet scrapers, hand sanding and orbital sanders. This material is fantastic it means I don't need to clamp the part down ( which gets in the way of sanding). I only need to clamp the out side of the jig on the framing or clamp them into the dog tail stops on the work bench I have.


Since I had to cut the front door flaps into their two folding sections before I could veneer them I had to make new cauls for each section. I wanted to be able to press more than one section up so like some of the other press jobs I made a top, middle and bottom press caul.



I had some MDF and Particle board left over from some of the other jigs so I could use this scrap to make the cauls.





Began to run out of offcuts so I had to use some other scrap that I had lying in my work shop for some time. This was 25mm MDF, even though thicker than the rest of the other caul parts It could still be used and would still do the job properly. I have found that this station has been quite helpful especially cutting unusual part shapes.


Sanded the edges of the cauls so they were not sharp with the orbital sander.



Had to covered the glue side faces of the cauls with baking paper. This would ensure that the veneer would not stick to the caul faces. A lot of moisture is drawn up through the veneer. The baking paper is just acting as a barrier to stop the veneer from gluing to the cauls. I find it is a lot better than news paper or butchers paper since it would stick to the veneer which cuts down cleaning time.



Finishing off the last covering for the new press cauls for the front door flaps.

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