24-04-2011, 10:50 AM
Hi,
Having successfully made the stringing all I needed to do now was to fit it. The more I thought about this the worse it became and the problem kept me awake in bed for many hours. It would have been possible with a great deal of care and patience to cut the straight grooves using a craft knife and straightedge but the rounded corners proved to be a major headache. I spent hours surfing the web for information but couldn’t find any so once again I was totally on my own.
I’ve owned a router for a few years but have never been a router enthusiast and only used it a couple of times but after much thought decided the router was the way to go and even this was not going to be easy. I measured the new stringing thickness and it was 0.085” (85 thou). The smallest diameter router cutter readily available is 1/8” dia (.0.125”) so I had a router but no suitable cutter.
Router cutters are manufactured to extremely close tolerances and mostly are tungsten carbide tipped or solid carbide although high speed steel cutters used to be available. My router is fitted with a ¼” collet and I wondered if I was just day dreaming because I decided to make a bespoke router cutter to suit my stringing. I visited Blackgates Engineering and bought two lengths of ¼” dia silver steel. Silver steel is made to high precision and this would take care of the cutter part that fits into the collet. Silver steel is available in a selection of diameters and is supplied in 13” lengths; it is reasonably priced and used extensively for making cutting tools and it can be hardened and tempered producing cutters very similar to high speed steel.
[attachment=942]
Home made router cutter.
A length was chucked in the Myford engineering lathe and set to run true; with a carbide tipped tool in the tool post the end was reduced to exactly 0.085” dia at ¼” long measured with a digital vernier dial. The steel was then placed in the engineering vice and a length matching a new router cutter was cut off using a hacksaw; the sawn end was trued in the Myford. Now I had the basic shape with two accurate diameters all that was needed was to add the cutting edges. The steel was returned to the vice and very carefully a flat was filed leaving just under half the original diameter; the cutting tip now looked very fragile but I decided to add a taper towards the end thinking this would give a shear cut? The end of the cutter was then given a chisel edge this edge being also angled slightly to allow the cutting edge to cut but prevent rubbing of the non cutting edge; to get this angle correct the rotation of the router was checked because to get this wrong would end up with a cutter that actually rubbed and this would quickly destroy the cutter due to excessive heat build up. At last I had a home made router cutter in my hand.
Mounting the cutter into the router I was delighted with the test cuts; the cutter plunged very well and left a nice clean cut; I hadn’t bothered to harden and temper the cutter as this would be a one off job and considered the silver steel tough enough to cut the grooves required.
[attachment=943] [attachment=944] [attachment=945]
Routing under way. Making router guide. Router guide clamped in position.
It was a real test of my nerves as I cut the straight grooves against a guide as one slip would ruin the job and I was very much aware from previous experience that a router has to travel in a certain direction in order for it to remain in close contact with the guide; get the direction of cut wrong and there is every chance the router will drift from the intended line. I was over the moon and amazed at how well cutting of the straight grooves had gone but now I was quickly pulled up as the rounded grooves proved extremely difficult. There was no margin for error; these rounded grooves needed to run perfectly into the straight grooves and also track perfectly around the veneer joint. This one problem alone absorbed a great amount of time but in the end I resorted to using tracing paper and making MDF guides; I had never done anything like this before and never seen anyone else do it either; the problem was further compounded by aligning everything up and clamping down but by lowering and locking the cutter to just kiss the surface of the veneer I was able to traverse around the guide and watch the cutter ensuring it was truly centred before switching on and completing the cuts. Doing the veneering really tested me to the limit but cutting the stringing grooves took ten years from my life; it was full of stress; would a home made router cutter actually work; would the cutter cut without a great deal of vibration? Determination and a great deal of patience won through in the end and the grooves were finally cut to 0.060” deep. (60 thou).
[attachment=946] [attachment=947]
Not easy. Mitre line at 45 degrees.
The stringing proved a tight fit; the groove was filled with woodworking adhesive and the string pressed fully home with the aid of a rubber roller ensuring the string went right to the bottom of the groove; this forced out a lot of adhesive which was quickly removed with a damp cloth. Cutting the stringing to length was yet another problem to resolve; as the stringing is laminated the craft knife wouldn’t give a clean end; trying to use a gents saw left a rather ragged cut and mitred joints also needed to be cut. Fortunately my friend David (Yorkie) had very kindly made me a splendid disc sander attachment for my DML24 woodturning lathe and proved worth its weight in gold trimming the stringing ends to perfection; a 45 degree pencil line was drawn onto the sanding table and the string was aligned with this for the mitre cuts; the disk sander was a joy to use and made a difficult job very easy.
With stringing added to both panels the panels were put away overnight in a warm place to allow the glue to harden; it was still very cold in the garage and I felt frozen most of the time; it was with a great deal of relief that I could come into the bungalow and thaw out but the pleasure of knowing I had finally succeeded in one of the hardest parts of this restoration was immense.
[attachment=948] [attachment=949]
Scraping sure looks rough. Scraped flush and perfect.
The following morning I clamped each panel in turn onto the cast iron bed of my Startrite combination woodworker and set to with a freshly sharpened cabinet scraper bringing the stringing flush; at first this looked terrible but as the stringing came down flush all the ragged edges suddenly disappeared leaving the stringing in all its glory. All through this restoration so far it has been a case of worry and stress followed by great success. Looking at the stringing now fitted it doesn’t tell the story of the vast amount of work it caused but it was well worth it and I learned a great deal.
[attachment=950]
Panel completed.
What a learning curve this had been so far; up front I thought I had little chance of pulling this off but now as I looked at both panels veneered both sides with inlay panels; cross banding and stringing I was filled with deep satisfaction and pride; the stringing had gone home perfectly with not a single gap anywhere. I still had a long way to go but with the two new cabinet side panels completed I was well on my way after all I only now had to fit the side panels and finish the cabinet off. The next instalment will cover fitting the panels. So far this restoration has been highly difficult but not impossible. By now I was sleeping and breathing this cabinet as it had taken over my life; the ice and snow made the work so much harder but I wasn’t going to let it beat me.
Kind regards, Col.
Having successfully made the stringing all I needed to do now was to fit it. The more I thought about this the worse it became and the problem kept me awake in bed for many hours. It would have been possible with a great deal of care and patience to cut the straight grooves using a craft knife and straightedge but the rounded corners proved to be a major headache. I spent hours surfing the web for information but couldn’t find any so once again I was totally on my own.
I’ve owned a router for a few years but have never been a router enthusiast and only used it a couple of times but after much thought decided the router was the way to go and even this was not going to be easy. I measured the new stringing thickness and it was 0.085” (85 thou). The smallest diameter router cutter readily available is 1/8” dia (.0.125”) so I had a router but no suitable cutter.
Router cutters are manufactured to extremely close tolerances and mostly are tungsten carbide tipped or solid carbide although high speed steel cutters used to be available. My router is fitted with a ¼” collet and I wondered if I was just day dreaming because I decided to make a bespoke router cutter to suit my stringing. I visited Blackgates Engineering and bought two lengths of ¼” dia silver steel. Silver steel is made to high precision and this would take care of the cutter part that fits into the collet. Silver steel is available in a selection of diameters and is supplied in 13” lengths; it is reasonably priced and used extensively for making cutting tools and it can be hardened and tempered producing cutters very similar to high speed steel.
[attachment=942]
Home made router cutter.
A length was chucked in the Myford engineering lathe and set to run true; with a carbide tipped tool in the tool post the end was reduced to exactly 0.085” dia at ¼” long measured with a digital vernier dial. The steel was then placed in the engineering vice and a length matching a new router cutter was cut off using a hacksaw; the sawn end was trued in the Myford. Now I had the basic shape with two accurate diameters all that was needed was to add the cutting edges. The steel was returned to the vice and very carefully a flat was filed leaving just under half the original diameter; the cutting tip now looked very fragile but I decided to add a taper towards the end thinking this would give a shear cut? The end of the cutter was then given a chisel edge this edge being also angled slightly to allow the cutting edge to cut but prevent rubbing of the non cutting edge; to get this angle correct the rotation of the router was checked because to get this wrong would end up with a cutter that actually rubbed and this would quickly destroy the cutter due to excessive heat build up. At last I had a home made router cutter in my hand.
Mounting the cutter into the router I was delighted with the test cuts; the cutter plunged very well and left a nice clean cut; I hadn’t bothered to harden and temper the cutter as this would be a one off job and considered the silver steel tough enough to cut the grooves required.
[attachment=943] [attachment=944] [attachment=945]
Routing under way. Making router guide. Router guide clamped in position.
It was a real test of my nerves as I cut the straight grooves against a guide as one slip would ruin the job and I was very much aware from previous experience that a router has to travel in a certain direction in order for it to remain in close contact with the guide; get the direction of cut wrong and there is every chance the router will drift from the intended line. I was over the moon and amazed at how well cutting of the straight grooves had gone but now I was quickly pulled up as the rounded grooves proved extremely difficult. There was no margin for error; these rounded grooves needed to run perfectly into the straight grooves and also track perfectly around the veneer joint. This one problem alone absorbed a great amount of time but in the end I resorted to using tracing paper and making MDF guides; I had never done anything like this before and never seen anyone else do it either; the problem was further compounded by aligning everything up and clamping down but by lowering and locking the cutter to just kiss the surface of the veneer I was able to traverse around the guide and watch the cutter ensuring it was truly centred before switching on and completing the cuts. Doing the veneering really tested me to the limit but cutting the stringing grooves took ten years from my life; it was full of stress; would a home made router cutter actually work; would the cutter cut without a great deal of vibration? Determination and a great deal of patience won through in the end and the grooves were finally cut to 0.060” deep. (60 thou).
[attachment=946] [attachment=947]
Not easy. Mitre line at 45 degrees.
The stringing proved a tight fit; the groove was filled with woodworking adhesive and the string pressed fully home with the aid of a rubber roller ensuring the string went right to the bottom of the groove; this forced out a lot of adhesive which was quickly removed with a damp cloth. Cutting the stringing to length was yet another problem to resolve; as the stringing is laminated the craft knife wouldn’t give a clean end; trying to use a gents saw left a rather ragged cut and mitred joints also needed to be cut. Fortunately my friend David (Yorkie) had very kindly made me a splendid disc sander attachment for my DML24 woodturning lathe and proved worth its weight in gold trimming the stringing ends to perfection; a 45 degree pencil line was drawn onto the sanding table and the string was aligned with this for the mitre cuts; the disk sander was a joy to use and made a difficult job very easy.
With stringing added to both panels the panels were put away overnight in a warm place to allow the glue to harden; it was still very cold in the garage and I felt frozen most of the time; it was with a great deal of relief that I could come into the bungalow and thaw out but the pleasure of knowing I had finally succeeded in one of the hardest parts of this restoration was immense.
[attachment=948] [attachment=949]
Scraping sure looks rough. Scraped flush and perfect.
The following morning I clamped each panel in turn onto the cast iron bed of my Startrite combination woodworker and set to with a freshly sharpened cabinet scraper bringing the stringing flush; at first this looked terrible but as the stringing came down flush all the ragged edges suddenly disappeared leaving the stringing in all its glory. All through this restoration so far it has been a case of worry and stress followed by great success. Looking at the stringing now fitted it doesn’t tell the story of the vast amount of work it caused but it was well worth it and I learned a great deal.
[attachment=950]
Panel completed.
What a learning curve this had been so far; up front I thought I had little chance of pulling this off but now as I looked at both panels veneered both sides with inlay panels; cross banding and stringing I was filled with deep satisfaction and pride; the stringing had gone home perfectly with not a single gap anywhere. I still had a long way to go but with the two new cabinet side panels completed I was well on my way after all I only now had to fit the side panels and finish the cabinet off. The next instalment will cover fitting the panels. So far this restoration has been highly difficult but not impossible. By now I was sleeping and breathing this cabinet as it had taken over my life; the ice and snow made the work so much harder but I wasn’t going to let it beat me.
Kind regards, Col.
