trunnels

[S/V Laura Ellen]

I have been reading info on trunnels from the forum archives and have come to the conclusion that trunnels may be the answer for refastening S/V Laura Ellen. Laura Ellen was fastened with iron (steel) screws, which have rusted over the years.
Some postings have referred to a source of pre made trunnels being advertised in WB, but I am unable to find the ads they were referring to.

Does anyone know the source for premade trunnels (1/2 ")? If I can't fing pre made trunnels I was planning on getting a dowel maker from Lee Valley (not a cheap alternative). Is this the best (cheapest and most efficient) way to make trunnels?

Allan

[Hughman]

The simplest trunnel maker is a stout steel plate with a hole in it, and a maul.

Cut your seasoned locust/osage orange/swamp oak blanks to a close fit, and bang em through.

[Noah]

ahhh boys....

I"ve made more trunnels than I can count whacking them through the old steel plate. It's the kind of task that makes a man out of a boy. 3 hits was all it took for me to take a 1" square down to 3/4" round. That's out of oak.

I've never made a trunnel for a boat, but I should think it would be done the same way.

Noah

[Venchka]

Aren't they spelled treenails?

Assuming you figure out how to make them, A & M Lumber in Ontario stocks black locust. Or did in recent memory.

Good luck!

Wayne

[ 07-26-2004, 12:04 AM: Message edited by: Venchka ]

[Hughman]

Originally posted by Dave Fleming:
</font><blockquote>quote:</font><hr />The simplest trunnel maker is a stout steel plate with a hole in it, and a maul. You have done that I suppose?

1 1/2 diameter winter cut White Oak.

</font>[/QUOTE]I said it was simple, not easy.

[bugeye]

Hi,
On Sultana, we fastened all of our planking with trunnels. We used a dowel maker, I think made by Bridgewood. You fed it square stock in one end and a perfectly round dowel came out the other. You could make one a mile long, if you had the stock for it. The dowel plate idea is attractively low-tech, but very labor intensive, and in my experience, you'll get alot of tear out, which will mean alot of little channels to wick water into the end grain of your planking. We made our trunnels exactly 1" in diameter and ground our augers 1/64th undersize to be sure that everything went together tightly. We would dip our trunnels in linseed oil immediately before driving, but if I were to do it on my own boat, I'd use antifreeze. Also, hose clamps are very handy for keeping less than perfect trunnels from splitting.
Good luck

[Ian McColgin]

The bigger the trennel and the larger the number to be made, the more likely that a dowl maker will be nice, but really, the old ways are not at all hard.

I've used a metal plate. I use three holes to get from square down to round. That way I'm not whacking off too much at a shot, not working at all hard, and if there is any squirrley grain I can see what to do about it.

Better than the plate, especially for the last pass, is regular iron pipe about 1" long, grind a bevel from outside for cutting and if you want to be really slick warm it a little and bang it on the cone (assuming you've your own anvil and attendent junk) to spread the back side a little.

If you've a big chuck drill or want to do it on the drill press, the job goes faster than banging and twisting.

The remarks about tightly fitting trennels are well taken. Consistent with Grana's conversion from traditional carvel to epoxyseambatten, I put a small groove in each trennel on the table saw as part of knocking out the square stock. I coat the trennel with epoxy and the groove relieves the pressure and is small enough that it fills up. The epoxy acts as a lube putting the trennel in and then seals the grain in the hole. I doubt that the epoxy actually adds any significant holding power to a well set trennel but it definatly makes me feel good.

G'luck.

[TimH]

I thought trunnels were sopposed to be slightly out of round so as not to split the wood they are holding together upon swelling. smile.gif

[TimothyB]

Miller Dowels are currently offered in three sizes and are intended for use with a corresponding Miller Quick-Drill Bit. Available in White Birch Cherry, Red Oak and Black Walnut.

Well, looks like you would need a special order if you wanted to use them for boat construction, given that none of the woods used are partucularly rot resistant, and the biggest size is a might small, but might be handy for a smaller vessel.

[JimConlin]

If you're doing a full refastening involving thousands of trunnels and are in a region where they still exist, I'd consider having my friendly local dowel mill manufacture them. The difference between locust and their usual birch/maple/cherry shouldn't upset their process badly.
There are still such mills in NH and ME.

[ 08-03-2004, 01:09 PM: Message edited by: JimConlin ]