Wood is ready for the pattern with the backer board attached in the 4 corner with counter sunk screws... I first roll out Scotch Brand packing tape to cover all the area.......There are lots of types of Scotch Brand packing tape. Storing, Packing and Shipping and maybe more but the shipping is thicker and doesn't tear apart as easy you are removing it off the wood. I then spray temporary glue on the tape then lay on pattern. Duck brand clear tape leaves too much stickum on the wood after it is removed to ever use it again. Scotch brand don't leave much sticky except where you sit there running the saw in the same place and the wood gets hot and melts a small amount of gu but not much. And that is the reason to use the clear packing tape to start with for if a person just sprays the wood and places the pattern on it then after the sawing it takes a long time to remove the sticky off the wood...Using lacquer thinner is about the fast way but hey the thinner is real expensive no a days...So go with scotch brand because I said to... And using just paint thinner takes all day to remove the pieces of pattern left after the sawing process.
The fastest way to make sure the holes I drill to attach all the loose pieces of wood to the backer board before I start running the scroll saw is take a very small drill bit like 1/16" or so and drill in through the pattern all the way through the back side then flip the board over and using a drill bit just a hair smaller width than the 3/4" long sheetrock screw threads and drill in through that small hole...The correct size bit to use if you hold the screw behind the drill bit you will only see just a small amount of the tip of the threads on each side of the drill bit.......This will keep the screw from busting the wood... A sheet rock screw is the same as a sheet metal screw as the threaded area is the same size from main holding area as it is all the way to the head.... Tapered threaded screws are too easy to get the wood busted as the screw goes
So now all the holes are drilled up through the backer board up in to the body to be carved. But first take a damp hand soap bar and rub some of the screw threads and this makes them go in better... now install all the screws then flip the board back over and start scroll sawing.
Going through the front of the pattern you see where the pieces will be left large enough to accept the screws without busting the wood.. Going this route you don't have to worry about the 4 screws in each corner.. Only saw out the outside pieces and leaving only the pieces what will be carved...
Next take the backer board off so you can start cutting away each piece to be carved..Separate the areas that needs to be cut down more than the adjoining area. And keep checking to ee if more screws needs to be installed as the inside pieces are sawn away.
The other way to make sure the screws are going in the correct location.. with the 4 screws holding the backer board in the 4 corners you can start sawing the wood away but leave the area of the body of the wood still attached to the 4 screws then once you get down around some of the clock that's jutting out, stop and counter sink a hole where there will be wood left after removing the waste area.
This way takes much more time as you will have to stop sawing when you get an area you know will accept a screw hole and go to the drill press and counter sink a hole from the back side of the clock and insert the screw....Then keep repeating sawing the outside until all areas have screws and the waste wood is sawn away...And each time you counter sink a new hole it needs to be hit with some sand paper to ensure smooth sliding on the scroll saw table..
I like to use a #5 precision ground Olson scroll saw blade for the outside sawing, they seem to last longer before they wear out and easier to guide making a straighter line. but don't know for sure then for all the inside cuts I switch to a flying Dutchman#3 blade which is thinner and don't make as wide of cut... The Flying Dutchman is better sawing curves.
The small screw holes left sticking out the front of the wood one can either fill them with something or like I do is add more holes in line or what ever and this is becoming my style as I like to raise each hole area like it was there on purpose..
This picture just shows how I take care of the sticky between the area where the pattern quits and the wood extends to...A person don't want to get stuck to the work area so after I spray the packing tape then install the pattern there is always an area left with sticky stuff left all the way around the pattern and trying to guide the wood while sawing is impossible so I just take some paper towels and cut strips and lay over the sticky.. Problem solved.
This picture also shows as I am fixin to drill small 1/16" holes through the pattern all the way through the wood so I can flip the wood over and counter sink the screw holes...the backer board does have to be installed before I drill the small holes through the front...!!!
Just sit and think how hard it would be to grind away certain areas if the pieces were left together...It will get clearer where the pieces should be sawn apart with each carving you make.
Don't know but I might be back with all kinds of corrections after I read this and it don't make sense, cents, or since.