Ferrule Lapping Tool

This tool is used to get even lapping across the entire slide area of a fly rod ferrule. When ferrule sets are ordered, many suppliers offer to size and lap in the male ferrule to fit the female ferrule. With a two tip rod you have two male ferrules that need fitting. If you have a three piece, two tip rod you are making then you have three male ferrules that need sizing and fitting to the female ferrules.

Many fly rod makers prefer to fit their own ferrules. Ferrules are usually supplied at .001'' oversize to the ID of the female ferrule, and this needs to be worked down so it will fit snug inside the female. A little 'pop' sound is emitted when properly fitted ferrules are pulled apart.

You can fit your ferrules before or after gluing them to the fly rod blanks. Many find fitting them before the gluing process easier than trying to manage the length of the sections (blanks) while trying to fit the ferrules after they have been glued on.

This tool is designed to provide even pressure on the entire length of the slide area of the male ferrule to prevent tapering or uneven sizing of the slide area during the fitting process. By applying even pressure on the sand paper along the entire length of the male slide area you take the same amount of material off the ferrule as you approach the desired outside diameter.

Use 400 grit wet or dry sand paper initially to remove the bulk of the material off the slide area of the ferrule and when the female ferrule just barley fits onto the end of the male ferrule, start using 600 grit wet or dry sand paper until female ferrule fits onto the male but still quite tightly. Applying a little light oil to the wet or dry sandpaper makes the removal of material a little easier.

Switch to 1000, 1200 or even 1500 sandpaper to get the final tight fit to the male/female ferrule then polish with a little metal polish applied to fine 0000 steel wool.

This ferrule lapping tool is made of hardwood (Oak) and all the supplies were purchased at our local ACE Hardware store.

3/4x1-1/2 inch oak hardwood strip cut in half the wide way (end up with 3/4x3/4x3 inch blocks)

1/4-28x3 or 4 inch screws (2 each)

Medium pressure springs (2 each)

1/4 inch flat washers (4 each)

3/32 inch steel rods

1/4-28 wing nuts

150 grit sandpaper

400, 600 & 1200 grit sandpaper

thin flat washer for spacing

Cut 3 inch length block from the hardwood.

Cut lengthwise so you have 2 equal width pieces. Sand if necessary.

Mark "IN" on two uncut surfaces, These will be the surfaces facing each other when completed. These should fit cleanly together with no gap.

Place the marked "IN" surfaces one on top of the other in a machinist vise to keep then secure during the drilling phase.

Mark and drill 2 holes with a #8 drill 3/4'' in from the outer edge. This is the correct drill size for 1/4-28 tap but since this is wood and not steel, I wanted a tighter fit for the 1/4-28 screws that will be used. Drill clear through both blocks.

Re-drill through top block only with a 1/4 inch drill bit.

Push 1/4-28 tap through top block (some resistance will be noted so twist the tap through top block holes) and tap threads clear through the bottom block.

Mark and drill 2 holes with a #43 (.089) drill 1'' in from the outer edge for the alignment pins. Don't drill clear through the lower block. Leave approximately 1/4''. These pins also serve to hold the sand paper in place during operation.

 Remove the top block.

Cut 2 each 3/4'' lengths off the 3/32'' dowel rod and grind each to a slight point. Using a vise, press each one into one hole of the top block and the other into the opposite hole on the lower block. These pins will be used to keep the blocks in alignment and will help hold the sandpaper in place as you use the tool.

Use a 3/32'' drill bit in a hand vise to drill out the opposing hole in the top block and bottom block to receive the alignment pins.

Trial fit the two blocks together. You may use a rat tail file on the 1/4'' holes to allow the blocks to fit together smoothly. You may also apply dry soap to the screw threads and dowel pins to aid in smoother sliding the blocks together and apart.

        

Place a shim of a couple thicknesses of heavy sandpaper (I used 150 grit with a thickness of .0272'' total) between the blocks. This will give you some working clearance during operation of the tool.

Assemble the blocks together laying on their side in the drill press. Drill a hole through the middle of the two block halves with the sandpaper sandwiched between them.  To determine what size bit to use depends on what size ferrules you wish to fit together.

You will be using two thicknesses of sandpaper along with your male ferrule in the hole for honing. 600 wet or dry is approximately .00785'' thick so twice that is .01563''. Add this thickness to the OD of your male ferrule (IE: #14 = .25219'' before removing material) you drilled hole should be .2678'' or 17/64'' for closest diameter.

Example: to make a tool to fit #14 ferrules (14/64'') use a 17/64'' drill bit, and for a #11 ferrule (11/64'') use a 13/64'' drill bit.

Remove drilled block from machinist vise after drilling honing hole, disassemble and remove shimming sandpaper.

Insure blocks separate and close together smoothly.

Cut 3/4'' wide strips of 400, 600 and 1200 wet or dry sandpaper to use in your new tool. Cut these into short strips that will punch over the two dowels and extend into the half hole of each block (see photo).

At this point it is a good practice to mic the OD of the male ferrule and record this dimension. after a few rotations of the tool against your ferrule, you will want to measure the OD again to determine how much material you are removing.

Assemble the tool squeezing the male ferrule between the blocks against the sandpaper. Install the springs, washers and wing nuts.

Screw the wing nuts down against the springs to apply sanding pressure to the ferrule, but only minimally.

Slide shim washer over the male ferrule. The ID of the shim should be small enough to stop at the inside end of the slide length. This shim is used to prevent the tool from riding up over the slide and onto the shoulder of the ferrule.

You may operate the tool manually around the circumference of the ferrule or mount the ferrule in a lathe to apply the rotational force as the tool hones to outside diameter. Stop often to check that the honing process is removing the same amount of material along the entire length of the slide area on the ferrule. Also try to fit the female onto the male ferrule to determine the tightness of the fit.

CAUTION: Approach the removal of the material from the slide of the male ferrule slowly and try to fit the female ferrule often to achieve the desired fit. You can accidently remove too much material off the slide of the male ferrule rendering it too loose to use on your fly rod!