Thursday, 2 May 2013

Hand veneering stage 1 part 2 veneering with wenge

( had to break up into another part since blog does not like to save posts with heaps of information)

I changed some of the veneer pieces around since with this new orientation the grain matched a lot better.

I decided to draw a 20mm offset around the veneer parts for the doors that would act as the finished size before timber edging was added.

I needed to see whether the grains from the front door flap and the back door would line up. Even though it is still a bit rough it would give a good indication as to whether the grain between the doors would match up.

Unfortunately they didn’t up as well as I wanted them to but I was not too fust by this. Moving them so they would fit better would be totally unnecessary due to the extra time it would take for re arranging.
I applied water to the veneer face of both the front door flap and the back door just where the over lapping section was. The water was to act as an oil finish and would roughly show what the grain and colour would look like when a finish was applied. Although when oil is applied to the wenge it is a lot darker than this.

This is a better view of what the water looks like on the wenge. Now I’m not too fust that they don’t completely match up. Wenge has a pretty even colour about it and even grain when quarter cut with most of it. It’s very hard to pick up the grain alteration if looking for it. Plus with the added darkness to it will make it even harder. When the cherry blossom marquetry is added it will make it even harder to spot since the vocal point will be totally drawn to the marquetry. The cherry blossom marquetry will consist of reds and yellows. So when placed with the wenge and oiled over it will stand out heaps, which is the effect I want it to have. The main focus of when the cabinet is closed is on the cherry blossom marquetry.

Now if I was using a blond timber and crown cut this would be a totally different story and the grain orientation would have to be done differently. For this veneer placement I used slip matching. Normally with quarter cut veneer you use book matching but I could not do this due to the other side being poorly milled. The knives obviously were blunt and had kinks in them.

This would be a far better way to match up the grain even though there is a bit of off cut. But the effective grain matching would totally out weigh the amount of off cut. Although like the other previous process stated this really only could be done for the front internal veneer section of the doors.

 I could have done this with the wenge but again the fact that I can’t mirror the left doors it would be pointless (due to other face of veneer being damaged). I really had to do good slip matching with all the doors. The most important sections that needed to match up were the bottom internal side sections of both the two front door flaps and back doors.

The blond timber edging and hinge gaping would also break up the doors a bit taking the focus away a bit and making it a bit harder to focus on to see whether the grain matched up 100 percent. But like I said before once oiled, the wenge becomes darker and when the cherry blossom marquetry is added the main vocal point will be drawn to that. 

Trying to put too much effort into getting the grain totally matched up when become pointless due to the grain focus being lost.

This is one way of displaying the veneers. Although this choice of layout does not completely line up the grain and colour 100 percent. This process is merely to prevent off cuts. But this can only be done if the other side of the veneer is as equal quality as the other face. Although this can really only be done for the front internal section. So over all this would not be the best choice to use especially with a crown cut blond timber.

Applied water to other sections of the doors to see whether the grain was showing up heaps.

Putting the camera on flash setting showed what the timber looked like with moisture applied to it a lot better and gave a better indication of what the grain and colour looked like. The work shop doesn't have the best light so doing this would give the best insight of what the grain of the piece would look like in a really light room.

Even though this is done roughly it still shows where the doors would be located in accordance to grain direction between the front door flap and the back door.

Had to take a variety of different photos and apply moisture to different sections of the veneers to see whether there was going to be any grain matching issues. Had to a bit of testing before I moved onto the next stage.

I was planing on using the trancing paper of the over lapping of the doors that I used for the magnet housings but this didn't really work that well.

I decided on moving onto the next process which was the clean the seam lines of the veneer parts for the doors before connecting together with the veneer tape. I used the jointer to clean the joints by placing the veneer piece between two pieces of timber and clamping it together. Same process that I used for the other veneer pieces.

Some veneer parts were easier to clean the edges more than others. This is because they were short enough in width where I could place a clamp in the middle of the two pieces of timber.

Having large veneers does get a bit problematic. At the moment the wenge is about 190mm to 200mm in width. The Figured maple is around the 300mm -320mm mark. I think I might make a router jig where I can lock the veneers in and machine the edges. Making this jig will mean that I can easily machine long veneer pieces and more than one piece at a time. I will also be able to use this jig with future veneer jobs down the track so it will be a good investment.

Making sure the veneer joints are good and tight. You don't want the joints to have high spots you want them to totally run parallel to one another and be tight with no or hardly any gaps. If there is a high spot it will mean that the joint wont go together properly. This can be problematic down the track when coming to pressing. Some times when pressed and the joint is not good it will leave huge gaps that show the substrate. This can be fixed but requires extra work.

The main issue is when one of the veneer pieces slips under another one and creates a very un sightly bump.
If the veneer pieces do not run parallel the grain match up will look funny and the joint wont hide as well. Also if not running parallel the veneer parts can seem tapered. This is not so much of an issue with the large pieces more of an issue with the smaller pieces. This is also why its important to try and hide the joint as much as possible. If the joint is spotted out so will the tapering.

When you have cleaned all the joints and are happy you can start connecting them together with veneer tape. Before I apply the veneer tape I take out any tapering from the veneer parts if needed.

Happy with the joints and are beginning to connect the veneer pieces together with veneer tape. Its always best to run small pieces of veneer tape across the veneer part connect line on the X axis first. You will find that you will be able to pull in the pieces together better along the joint and be able to keep it tight. Once all the short pieces of tape are placed across the joint you run one long strip right down the middle of the joint. I do this to create extra strength.

Never apply veneer tape to both sides. One reason is that it can cause a bump when pressed. And you will see the indentation of it under the veneer and you will not be able to get rid of this. Also if there is a gap you will see the white tape which will need to be removed for a finish is applied.

Once the whole veneer piece is connected together I place it on the substrate panel to make sure that it has not gone over the 20mm offset. If it has I would need to clean the outer veneer joint and attach another piece to it.

All pieces connected together and ready to be veneered to the substrate panels. Before pressing the veneers takes place I need to glue the magnets into the housings and glue the dowel plugs over them. Once that is done than I have to clean the plugs so they are flush with the substrate panels face.

I can go ahead and veneer the back doors but with the front door flaps I need to cut them down the fold line first, both the veneer and the substrate panels. This is because the fold line of the door flaps needs to be veneered first before the outer and inner faces are veneered. The outer and inner faces will cover the veneers edge that will be on the fold line face. This just makes things more neater.

While waiting to be pressed its best to place the veneers between the cauls and apply weight to it. This will prevent the veneers from buckling.

Before applying glue to the substrate panel and pressing down the veneer pieces the panel face needed to be scored and sanded. 240 grit sand paper and scored with the rip teeth of the Japanese hand saw. Lightly scoring don't need to do it heavy since you will cause large cavitys for the veneer to sink into and you will damage the teeth of the blade.

Needed to connect the two parts together to form the whole veneer piece that will be going on the bottom face of the top panel for the cabinet.

Spread out the polyurethane glue with the large painters scraper. But before doing this sprayed the panel with water. This will start the curing process of the glue and will require the panel to be pressed less since it will dry faster.

I figured this would be a good chance to test the shellys polyurethane since this panel does not get seen at all.

Taped the edges with veneer tape to prevent the veneer face from moving when being pressed up in the vacuum press. 

Placed the job between the cauls and placed vacuum press rubber over it and sucked air out of press.

Job will be left in the press for a fair while to make sure the the glue fully drys.

Sprayed down the veneer face with water to break down the adhesive in the veneer tape which will make it easier to scrap off with the cabinet scraper. This was the under neath face for the top carcass panel that does not get seen at all.

Removed majority of the tape the other areas of tape and glue will be removed from the orbital sander.

This is what you don't want to happen with the out side veneer. It is lucky that this does not get seen. This resulted from one of the veneers accidentally going under the other other layer in the joint when being pressed up. This was from the mistake of applying moisture to the veneer and it started to buckle up. If I had not done this this probably would not have happened.

If this happens on the wenge the section will need to have the marquetry displayed over it. Although I can not afford to have this happen on the figured maple.

Even though this does not have anything to do with veneering. These were the steps that were needed to be taken to get to the stage of veneering the fold line edges on the front door flaps.

The front door fold lines needed to be veneered first before the substrate faces were veneered over. This is because when the front doors are folded up you would see the veneer edge from the fold line if it was put on second after the substrate veneer faces. There is nothing structural about this its more neatness.

I needed to make a template to transfer the final image of the front section of the doors. This template would not include the timber edging. I really just needed to transfer the fold line that I needed to cut down.

Now I will not be using this template as the final template to cut off the 20mm offset from the doors when all veneering is done. I will be getting templates cut out from a sheet of plywood backing from the nesting machine at work. ( the nesting machine is a form of CNC) This is so that the parts will be totally accurate.

My saw blade on the Festool circular saw blade is about 2.2 mm in thickness. The saw blade would be running exactly right down the middle of the cut. This would position roughly 1mm of cut on each side of the folding parts. Now this means when cutting off the 20mm offset from the doors, I need to make sure to add another 1mm to each fold section due to loosing it with this cut.

Checking thickness of blade on circular saw.

Both the fold line cut needed to be drawn and the outside boarder of the cut line from the circular saw blade. This out line boarder cut line would show me where I need to place the cutting edge of the saw guide. 

I decided to do a test cut first on a scrap piece of timber that was 15mm in thickness, the same thickness as the doors I was about to cut. This would allow me to set the blade to the right depth. The blade depth needed to just sit below the job to avoid splitting. More so this test was more to check whether the saw was cutting at 90 deg. The fold line needed to be totally clean and straight. If it wasn't the doors would not close properly and the fold joint would look un neat.

All clamps in position and ready to make the cut. There was a lot of double checking since I only had one shot at this.

Cut made and now front door is in two parts the top flap and the bottom flap.

This is the right door flap. This is how it would fold. The top section comes down than the whole door folds down from the bottom. 

This is the end fold position for the front door flap. The top section will show the internal veneer of the cabinet which is the figured maple.

Second door (left door) cut into the 2 folding parts.

Both front door flaps in folding position.

Now there was a bit of a problem.

One of the magnets is out by 5mm with its partner. I was thinking this would not matter. At the time I didn't think that this would do this due to the other magnets balancing out and pulling them selves to their mates, instead one section has become weak due to incorrect magnetic field spacings and is pulling the flap more from one side.   Whats happening is that the central part of the magnet wants to go to the central part of its mate. This pushes the fold section out a bit. Its actually pushing it out by 5mm the same amount as to how far out the magents are between one another.

Now of course there is nothing holding it back since the hinges are not installed yet. Also with the hinges when installed it will create a 2mm gap between the two folding parts. I wont remove it now since I might be worrying about nothing. I'll have to painfully remove it if I have to when veneer is over it and carefully take it out machining around it than under. But I can place the sakura inlay over it which than u wont see it. The hinges I plan on using are quite strong so it should not matter.

The magnetic field must have its strongest point in the middle of the magnet. I wont have to worry about the hinges attracting to the magnets in their magnetic fields. This is because the hinge hard ware is brass and is not attracted to magnets due to not being a ferromagnetic material like iron.

 Began sanding down the magnet housing side faces of the front door flaps. These needed to be totally flush before the veneer was laid down.

I used a 100 grit sand paper since this would make short work of the end grain of the dowel plugs also a great grit to get rid of the texter marks and pencil marks as well.

Since it was a more abrasive grit I needed to keep the orbital sander moving all the time and never staying in one place for too long. I first went across the grain a few passes than finishing it off by going with the grain a few passes.

There had to be more care taken when sanding the front door flap sections especially near the fold line. There was no offset near the fold line so I could not stay long sanding in one area near there. I had to be really careful near that edge.

You usually have everything over size when veneering. This is because when sanding your pron to round the edges slightly if your not careful. Once sanding is complete you than cut down to finish size. So this is why I had to be really careful near that edge. If the edge was rounded slightly this would stick out heaps.

Back doors sanded and ready to be scored than sanded with 240 grit than glued and pressed with the wenge veneer.

Bottom section of right door finished. 

Finished top section of front right door flap. Checked to see if everything was level and there was no rounding on the fold line.

Just remembered I needed to bog the gaps that showed up around the dowel plugs in the housings. These gaps were very small but I wanted to fill them just encase the veneer would sag into them. Sadly this meant re- sanding the other parts again. I had to leave the builders bog for a while to wait till it fully cured before re sanding.

Now I needed to cut down the veneers for the front door flap sections. 

To make sure that the grain would match up properly when the two door flap sections go back together I made a chalk triangle. This would show exactly were the grain needed to match up to.

I didn't want tare out so I decided to clamp down the straight edge to the veneer piece to ensure that I would obtain a very clean cut.

Cut made now parts are ready to be pressed.

Ready to cut right side door section veneer in half for the two folding sections.

Parts cut and now ready to be veneered.

There were a few things that I needed to do before these face veneers could be pressed down onto the substrate. First was to veneer the fold edge the second was to make some new clamp cauls for these parts.

Began to score and sand the glue faces on the substrate for the wenge on the front doors to create and effective blue bond.

I wanted to keep the fold line edge as clean as possible so I place blue painters tape over the whole edge to prevent any expanding glue from the polyurethane from getting on it.

Once water was placed over the face and the glue was spread out evenly it was time to lay the veneer over it.

With one of the top sections of the doors I had to be careful with aligning the veneer onto the substrate. Some off it had to be offset from one side this is due to some of the veneer being crooked. I didn't want the door to look crooked from seeing one of the veneer sections tapering off. So the veneer is place on this one for a reason. I used the paints tape to prevent the veneer from moving when placed into the press.

I also wanted a bit of the wenge veneer to stick over the edge. This meant that I would have something to play with when cutting it back.

Pressed up both top sections of the front doors in the press and needed to leave for four hours. 

Once the four hours was up I was ready to press up the bottom sections of the front doors with the wenge veneer. Followed the same steps as previously stated.

Placed in cauls and ready to be pressed.

Needed to cover the pressure cauls for the back doors with baking paper on the faces that would come in contact with glue.

Pressure cauls covered with baking paper and now are ready to press up the veneer onto the substrate panels for the back doors.

Before applying glue on the panels they needed to have their glue faces scored and lightly sanded with 240 grit sand paper.

First wet the glue face with water from the spray bottle than applied the polyurethane. The polyurethane still needs to be lightly spread out with the paint scraper.

Before being placed in the pressure cauls the veneer needed to be taped down to prevent slipping in the press.

Job placed in press and will be left in there for four hours. Luckily the job justed fitted.

Needed to clean off the over hang wenge that sat over the figured maple veneered edge (fold line).

I tried a few different ways of trying to clean the over hand down to being flush with the veneered edge cleanly. Most of the processes were slightly chipping out the veneer.

I came up with one idea where using a sharp chisel and placing it down the edge of the panel over the top of the over hanged veneer. With a heavy hit with the brass mallet it took the off cut off really cleanly. I fount it had an even  better result when dipping the tip of the chisel blade into water first than made the cut.

Even though I did this some of the veneer on the edges were braking off.

I think I had set my self up for failure before I even started. The wenge brakes out very easily especially at he ends of the veneer. I thought that since this fold line was down the middle of the job I would be able to get a good bonding  and there would not be any break out.

I think that even if I continued with it and oiled it there could still be chance that these edges could chip out.

I decided to use my Japanese knife and make a score line which would break the veneer and prevent even further brake out. I wasn't really getting any break out from the chisel since I had paints tape on the other side which would cushion the break.

Sadly my line tapered out a bit and I had cut off about .8mm-1.00mm of the wenge from the door.

I could easily fix this but I'm thinking it might not do that much since the edge will still be quite weak.

I think what I was going to need to do was route out a rebate section on the fold line and place in some stringy inlay. I thought at first maybe involving some red ( it would not be this red, a reddish timber that is the same for the splines would be used.) This sticks out too much and doesn't fit in with the whole idea of keeping the joint hidden.

Had a bit chip out on the front corner which I was lucky enough to glue to the chip back in.

Even though I wanted the joint hidden as much as possible I had also the problem of keeping the edge safe from chip out. I think If I added a very small timber edging about 2mm it would prevent any further break out since it would be providing a barrier to the edge. So at the joint it would add up to 4mm 2mm on the top flap and 2mm on the bottom flap.

I just made a small black strip to see what it would look like.

Placed a piece of wenge veneer strip over the joint to see what it would look like roughly. I dont think this would stick out too much. For this edging I would not be using veneer but a small piece of wenge timber edging.

At the moment now seeing that the wenge is so brittle and weak and breaks out heaps. I think trying to create a break out barrier is more important than trying to heavily hide the fold line.

Due to the dark colour the wenge becomes when Danish oil and wax is applied It should be ok. The fold line will only be noticeable when you go right up to it.

Plus adding in this edging will mean it will take off some of the edge that maybe slightly rounded when sanding happens.

I think If I was too do this again I would make these two flaps separate so I could get an offset on the fold line that I could take away. I would than add on the figured maple veneer strip to the fold line than machine a trenching to add in the timber strip to act as the grain break.

A while ago I mentioned that I may have problems with the sides that were veneered with the wenge as I used PVA tight bond glue. Unfortunately I did have problems due to the bleed out and it shows up too much and does not become hidden like the polyurethane glue. This has now required me to cut more veneer. A costly mistake. Luckily I had plenty of wenge veneer left over to play with.

Cutting the veneers to size for the sides. I only had to use 2 of the leafs in the pack.

Veneer for the sides cut out marked and ready to have the joints cleaned.  Before I press this up I will be talking to my teacher if there are any options he can think of to clean the veneer.

I did a little more testing with the mentholated spirits since this is going to be the closet thing to an oil besides an oil. It does not show up as bad when u place water over it but you can still see the sections they come up as little resin puddles.

I still will be using the white veneer tape for the wenge and not the blue painters tape. I find that the adhesive from the blue painters tape gets too caught up in the pores of the wenge and is quite hard to clean out of the vein cavities.

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