Thread: Caulking Irons - Air

Originally Posted by Kingfisher

Hi all,
Another beautiful on night on the river - wouldn't be dead for quids!!
However, between glasses of wine, one's mind returns to what keeps me afloat!
And Kingfisher is due on the slip again soon - in fact the occasional weep or leak reminds me she's well overdue.
I'm anticipating the normal routine of paint, caulking and tar. Not much has changed in a few hundred years except tar & pitch have been mostly replaced with bitumen. And caulking can be done with AIR tools!
Which brings me to the point of all this. Previously all caulkng has been done by hand. I quite enjoy rolling oakum and swinging a mallet for hours on end (truely!). But with slipping fees being expensive by the day I'm keen to augment the tool box with a set of air powered caulking irons.
The system looks simple - a standard set of caulking iron heads attached to a shaft which fits into (what I assume is) an air chisel.
But there's no way I'm cutting up my caulking irons to convert them.
So, does anyone know where caulking irons can be found or made for a reasonable price? They're a very basic tool, but the prices online seem quite obscene.
Maybe I just need a friendly blacksmith !?!
Any thoughts or ideas welcome.
Mark

Hi Kingfisher,
I only use an air chisel attachment for jerrying out pitch, putty or oakum but only as width allows, the jerry iron attachment is simply a piece of file welded to one of the bits that came with the pneumatic chisel hammer tool. I used 316L stainless rods for the weld in the way of a pad weld to either side of the join between the file piece & bit, effectively scarfing weld metal for the join & then ground smooth & fair. I've got a couple of irons that are "adjusted" stone chisels from the hardware. Air caulking might take some time to get the hang of, I can see some speed being made in hardening up but you'd have to be superhuman to make or "nip" the oakum into the seam at the rate an air hammer goes off at.
All the best with it from Jeff.

Originally Posted by waikikin

. . . Air caulking might take some time to get the hang of, I can see some speed being made in hardening up but you'd have to be superhuman to make or "nip" the oakum into the seam at the rate an air hammer goes off at . . . .

Agreed, and I'll add caulking is a feel thing, more then anything else. Sound plays a role, but more as a catch for a bad hit or a soft patch of seam. I can't imagine you'd be able to feel much with an air chisel. I'd also think you could easily drive in way too mach material. It would be worth it for me to give it a try, but having not used this tool yet, I have my doubts.

A couple of things to add, particularly to deck work. When I developed my Pneumatic jerrying iron I was Shipwright to tall ship "James Craig" & had around 2.6 kilometers of deck seam to look out for. Typically jerrying out would have to happen before smoko(9.00 am) as once the sun warmed the pitch it was a bit sticky(a tin of oakum ends with gum turps & a touch of linseed oil would slick up the irons & clean them). The rapid action of the air chisel/hammer would generate some heat of it's own, also if the area was "good" & the pitch relatively sound(but being reworked as part of a general repair program/continuity) you'd have to "quarry" the pitch from the seam- that is to take a bite say 1-1.5" & jerry out back towards where you'd already cleared so as not to split out.
Recaulking would be by hand & progress within reach of the caulking box generally with 3 irons used- a making iron to nip/tuck/make the thread into the seam, a square edged but rockered hardening iron to consolidate the fibers & a reeding/grooved iron to finish(& tuck in the edges) 2-3 threads made up the schedule depending on the seam or some times just hardening down or just another thread might be added as required.
Paying up was done with ladles generally cut from a specially folded 410 gram tin with a lovely handle in timber, pitch/Jefferies Marine glue was cooked in a Sunbeam brand "bistro" cooker(the more recent Sunbeam deep fryers are OK but don't overload the depth or they struggle with heating capacity. The electric aspect added some safety fire wise). Scraping of the seam would happen the next morning. Since then I've also been convinced on the benifits of seam taping, & didn't believe until we did a time/motion study & saved plenty on clean up with the tape & also preserved some timber thickness to the deck(maybe not significant on 3" but on 1" it does count in life)
Regards from Jeff.

It's quite a common practice on the river here with the paddlewheelers. Even the old timber ferries were/are hardened with air.

Originally Posted by Kingfisher

It's quite a common practice on the river here with the paddlewheelers. Even the old timber ferries were/are hardened with air.

I'd heard that from one of the RMS surveyors that goes to the murray, for hardening stands to reason as you need some form of percussive force on the iron, I'd say that the air pressure would easily be regulated to whats required. Might pay to check out the equipment people are using especially in regards to the irons profile so you can advance in the seam nicely. & post your findings so we can all know.
All the best from Jeff.

Just a follow up on the above. Kingfisher has just been slipped and all caulking was done by hand. I employed an experienced caulker to help with the task and he informed me that standard practice now on the traditional steamers is to not only use air, but they have foregone the traditional tucking method as well. The oakum is just put in straight. I can't say if all the shipwrights have gone this way (not that there are many of them anyway) but some certainly are. Which I guess begs the question - why do we tuck the oakum?

Originally Posted by PAR

. . . and I'll add caulking is a feel thing, more then anything else. Sound plays a role, but more as a catch for a bad hit or a soft patch of seam. I can't imagine you'd be able to feel much with an air chisel . . .

I'll bet the old timers that caulked your boat have the same reservations I do, though I'm sure some have tried it. You can tuck or not. Generally you tuck when you need to and lay it in straight, when the seam is uniform and fairly straight and narrow.