Tool maintenance ... check for cracked ferrules

[Mobyturns]

Over on Sawmill Creek site there was a photo of a damaged bowl gouge handle with a split ferrule & a large split in the handle. The tool is recognisable as being from a prominent manufacturer.

This lead me to examine what was going on & what may have contributed to the "split" and what the likely outcomes of the hazard may be.

I came up with a combination of small factors - an archaic work practice; poor quality "brass" material in the ferrules, perhaps poor quality assurance / inspection, and a turner thinking "I will get around to fixing it" and possibly no feed back loop reporting the issue to the manufacturer.

I strongly suspect defective materials & outdated work practices during manufacturing are the major contributor to a dangerous hazard - the split handle.

Potential outcomes from this hazard range from replacing the handle, right up to a potential death. :oo:

As there have been several deaths :( of wood turners in the past five years or so where the cause is "unknown" or overly simplified as "the wood exploded" one contributing factor could be the turner loosing control of the tool! A split handle or ferrule will eventually fail, leading to loss of tool control.

:no: It is a dangerous practice to continue to turn with a split ferrule - you may get away with it for a while, but it will catch up with you eventually. A good quality ferrule is a couple of bucks - retail! Do yourself a big favour, replace them and don’t put it off.

As a result of the post I went & rechecked the ferrules on my large scrapers. I don't do many big bowls so mine are almost pristine. They exhibited the same hazard, a crack in the ferrule & you guessed it beside the punch mark. A few tools now have new handles & other handles now have new ferrules. :D

[hughie]

I would imagine if the ferrule had split along the punch line, then the quality of the ferrule should brought into question. In this case I wouldn't be surprised if the cost of brass ferrules hadn't driven choice here.

In today's world and the new technologies that exist I think we can move on from the punched indent to keep the ferrule in place, especially if very light gauge brass tubing in being used.

I use a combination of methods that have some basis in the older method of fitting ferrules. The ferrule is fitted to a slightly tapering handle and is driven home on the taper leaving a small amount standing proud of the handle generally around 1mm -1.5mm. There is a secondary taper, tapering toward the tool piece of around 25% of the length of the ferrule.
After the tool in driven into the handle I fill raised portion of the ferrule with slow setting Araldite, by slow I mean 3-4 days to fully harden. The Araldite seeps into the tapered portion over time and sets. I have been doing this for several years and have yet to have failure. I might add my style of turning is not genteel by any means, its more of a bull at a gate style to remove all the un-necessary timber as fast practicably possible.

[stuffy]

A bit more wood around the tang end of the tool helps too.

Some tools come with a ferrule that is just too small in diameter.

[dr4g0nfly]

A bit more wood around the tang end of the tool helps too.

Some tools come with a ferrule that is just too small in diameter.

To that I'd also add the length of steel set into the handle, I've seen as little as 2", barely enough to pass the ferrule. Yes I know that tool steel is expensive but the power that we can put through these tools means that the pressure against the inside the handle can be extreme, and mostly at the narrowest part.

[tea lady]

There is also the need to split the wood for the handle rather than just cut it so size so there is no grain run out. And not cracks in the timber. Specially at the business end.

[Paul39]

After reading the above I had a look at my most used tools.

The Crown 5/8 inch bowl gouge had a nice thick brass ferrule, the Penn State Industries Chinese 1/2 inch bowl gouge and 3/8 X 1 1/2 inch scraper had slightly thinner but still substantial brass ferrules, the Henry Taylor skew and scraper had very thin brass ferrules, and the Chinese 8 tools for $20.00 had thin punched tin can stock ferrules. All had a dimple in the side of the ferrule to hold it on.

I have big hands and arthritis, and also get hand cramps if I hold a small diameter tool for too long. I am putting fat long handles on lots of my most used tools. For ferrules; I have used recycled copper pipe, EMT (electrical metallic tubing), a piece of chrome plated tubing that was used in a store display, and tubing used as the top bar on chin link fence. One could buy couplings used for soldering copper pipe together. I checked prices on some larger ones and the quote made me weak in the knees.

I cut the tubing by putting it in the lathe, grabbing in the chuck on the drive end and using a big cone tail center on the other. A drive cone can be made by chucking a piece of hard wood and turning to suit.

I score the copper with a skew or pointed tool and the steel ones with a carbide tipped 60 degree point made for metal turning. I go about half way through then shut off the lathe and go around and around the rest of the way with a hack saw. The tubing could be taken out of the lathe and put in a vice for sawing.

I turn my handles so the ferrule is a snug fit and sand the inside of the ferrule with 80 grit to give it some tooth. I mix two part epoxy and coat the part of the handle to receive the ferrule and twist the ferrule on and back and forth to be sure the epoxy is smeared over the inside of the ferrule.

The next day I put the handle back on the lathe, polish the ferrule and take off any rough edges. I have a hollow tail center that lets me drill a 5/16 inch hole. If I need to go bigger I have a 1/2 inch drill chuck on a 2 Morse Taper to go into the tail stock and can make what ever size hole needed.

Holes for round shafts are made to a snug fit and epoxied in like the ferrule. Square shafts are drilled a bit under size and the hole filled about half with epoxy and tool driven in by whacking the butt end of the tool on the bench. I then poke saw dust down into the epoxy filled space between the square shank and the round hole.

Here is something I stumbled upon: http://www.thompsonlathetools.com/images/extra/TurningToolHandles.pdf

[Christos]

I prefer to make my own handles as the size needs to be bigger to accommodate the size of my hands.
I have use steel pipe for the ferrals that I picked up from the side of the road.

I think that most of the new turners need to make tool handles. Experiment with the shape, length and size.

[powderpost]

I use hard drawn copper tube 25mm and 19mm for ferrules. This is scrounged from the local plummer, cut to length and with a slight taper on the inside.
Jim