View Full Version : Replacing Fasteners
07-15-2001, 11:28 AM
I am in the process of refitting my ex west coast commercial gill netter that I have had for the past 12 years. I converted her to "pleasure" use when we first got her and have been using her constantly since. The old girl needed some interior refitting, since we now don't like the way we fitted her out the first time, as well as some general hull work so we hauled her and had her transported to our house where she now sits right outside my shop. I have draped a tarp around the hull and have a sprinkler system going under the hull to keep her damp so she will not dry out too much over the summer.
I have the interior almost totally gutted and have scraped and cleaned all the bilges looking for deterioration and have found very little and what there is can be fixed easily. I want to refasten and recaulk the hull since the boat will be out of the water and in my yard untill next spring so I want to do it up right.
What I am looking for comments on is the proposal to refasten the hull using 1/4 inch galvanized carriage bolts instead of screws or nails. The reason I have for this proposal is that it would seem to me to be far less invasive to the ribs if a small round hole were drilled in them rather than "forcing" a screw in or driving in a nail, even with pre-drilling. There are many places where the original nails have cracked the ribs at the point on insertion, not enough that it has damaged the rib but I don't want to take the chance of cracking them further.
The hull is 2" western red cedar over 1 1/2" X 2 1/2" oak ribs on 10" centers. The original fasteners were cut nails (galvanized I would think) that are starting to deteriorate. Since they are into oak, they will NOT pull from any area below the waterline no matter how brutal I get so I can only go on the general condition of other items like the thru bolts that hold the keel and keelson together, which was bad. I have already replaced all these fasteners which was fairly easy as I just added new ones next to the destroyed ones.
I am considering using the bolts as a very secure fastener that can't pull out since I can reach vertually all the areas within the hull now that the interior is stripped out to install the nuts and washers inside.
Do you guys have any comments on this suggested proposal ?
Thanks in advance for your comments,
John Tones MV Penta (high and dry)
07-15-2001, 12:42 PM
The men I apprenticed under learned their trade in the 20s and 30s. Much of our work was small commercial craft (under 60'). They drummed the following into my head. "Only bolt if you can't screw, only screw if you can't nail."
Some of the boats that came into the yard were more than 50 years old and iron fastened. The fasteners were sound enough that the boats were still earning their keep.
The quality of the fastener and good installation are important. Be sure to use galvanically compatible materials.
I would not be inclined to use bolts in this application. I don't believe they are needed. If the frames cannot take another fastener, then they should be sistered or replaced. If, as you say, the interior has been removed this doesn't really take long.
07-15-2001, 01:31 PM
Can't argue with the 'mantra' quoted by Bainbridgeisland but are you really talking about ***cut nails*** or Boat nails?
Cut nails are wedge shaped with a head no larger in width than the widest part of the body of the nail whereas true boat nails are rose headed with a destinctive tapered bulge for the majority of the length of the nail.
That bulge is what gives the tremendous holding power to the nail. Cut nails would be ever so much easier to withdraw even in Oak.
I doubt if you will be able to find true Swedish or Norwegian iron hot dipped galvanized boat nails today but you might search the 'net for a supplier in the Scandanavian countries.
Gonna be a bear to find real hot dipped fasteners in any case. Last time I was exposed to a repair job on a galvanized fastened vessel we had to send the fasteners out to be dipped and then the bolts had to be re-threaded prior to use as the hot dipped galv. filled the threads and the nuts would not go on then the threads had to be painted with oil based galvanized paint after in place.
In any case whatever fastener you decide to use just don't mix metals, ya folla?
07-15-2001, 03:20 PM
My boat (similar to yours but smaller) had a similar situation with fasteners. I had a good boatwright look at it, and when he got down to it, and got some planks off and could see the hidden face of the frame many looked like they wouldn't hold another fastener. To make a long story short we ended up replacing all of the frames, and I am glad we did. Once that committment is made and the covering board comes off, the work goes quite fast. I don't think it took any longer than it would have if we had tried to replace say a third of the frames singly. With two people working 6 to 8 new frames were going in each day.
I am also in Victoria, and we are still working on it so if you would like to see the operation email me.
07-15-2001, 05:30 PM
Sorry about the terms used for the existing fasteners, they are a steel "nail" that appears to be tapered - square in cross section and have what was probably a round or oval head. They do not appear to have had any sort of "bulge" to the shank but then again the ones I have pulled are all slightly corroded.
All the fasteners etc on the boat are galvanized steel with the exception of the cutlass bearing and rudder stock / fasteners which are bronze.
Ther is no real corrosion problem, just old age showing on the frastners that I have pulled but all in all I think that since the boat is in my yard and easy to work on, now is the time to refasten and I want to do it right.
I am very concerned about being able to get "good" fasteners, be they screws or nails, as all the local major suppliers are only able to get "off shore" stuff that I have no faith in.
I guess that I could try getting stuff from Jamestown etc but the thought of importing hardware into Canada sends shock waves thru me. Then there is the problem of what to do if you don't get what you need and it has to be returned - been there and never want to do it again.
As I said in my original post, my main reason for thinking about the bolts was to avoid causing stress to the frames (which are all in good shape now except for the minor cracks from original fastners) but then again maybe I am worrying about something that I should not be.
Thanks for the input so far, this list is great !
07-15-2001, 06:43 PM
John;Check out this site<http://nsonline.com/links/Marine_Guide/.
It lists various marine related businesses here in Nova Scotia.Of particular interest may be the sites for Scotia Trawler and The Lunenburg Foundry.They still service an active commercial marine industry and may be able to provide the fastenings you require,in Canadian dollars.They used to carry the proper galvanized boat nails and may still.
Best of luck.Earl
Sounds like you've got a good plan going. Reef all your seams, refasten and then re-caulk. The commercial boats generally have nice big scantlings, you usually have plenty of meat to work with. I'ld go with the galvanized screws or nails. The nice thing about screws is that you can pull a boat together instead of beating it together. Screws give you a better feel for how your frames are taking and carrying the new fasteners. Once you get set up with the drills and countersinks that you are comfortable with it will go well for you. You sound like a very capable person. Thru bolting your planks to your frames is usually saved as a last resort method of refastening. Don't do it. Good luck.
07-16-2001, 08:13 PM
Actualy, you would be far better off with the locust trenels or trunnels. Search and find the excellent threads on this. Drill the nails out with a hollow holesaw type bit, removeing most all of the bad wood as you do so, and replace with a lifetime fastening who's only cost is your labor. Other than haveing to make the tools for the job, it shouldn't take much of any longer than bolting.
07-17-2001, 12:36 PM
Ditto on not using bolts or machine screws to refasten the planking. Besides the things mentioned a main trouble with through-threaded fasteners is that there is virtually no way in the long term to prevent water penetration via the threads. Bungs won't do it, and setting the fasteners in epoxy leads to disaster if repairs are needed. Anything else will eventually leak.
Whatever you use, nails, trunnels, rivets or screws, make sure you have clean surfaces and a tight fit beween the planks and frames before fastening. Trying to close a gap between a plank and a frame by pounding a nail or a rivet or twisting a screw often doesn't work. And trunnels won't pull them together either.
07-17-2001, 02:00 PM
FWIW, fasteners in epoxy can be removed without much difficulty by heating them, since epoxy softens around 150F. Not nearly as disastrous as one might think.
(I'm not proposing fasteners in epoxy for Mr. Tones' boat, you understand; that sort of work is entirely outside my experience.)
07-17-2001, 11:57 PM
Thanks for all the input guys, this list is great.
Bayboat, how do you recommend pulling the planks and frames together without pulling planks off ? I am curious as I have never seen any methods for this explained in the publications. This was another reason I had for the bolts but you guys have convinced me otherwise with regards toi them.
By the way I got a line on a small hardware importer in Vancouver BC who apparently brings in quality marine fasteners including galvanized so will have to follow up and will let the list know of what I find.
07-20-2001, 06:32 AM
JA:One trick for pulling the planking tight to the frames is to use a temporary through bolt tightened down sufficiently and then fasten the adjacent screws,nails or whatever.The bolt is then removed and a fastener installed or the bolt hole filled and plugged.This works well with thick planking and substantial frames.Be careful not to damage your cedar planking.You may want to use a large flat washer or pad under the head of the bolts.
If you can't do the temporary through bolts then try the old shores and wedges routine.If the vessel is blocked up good and sturdy run a shore,(A good solid piece of wood or whatever),from the sprung plank to solid bearing on the floor or ground and drive in a wedge to draw the plank tight.This works but can clutter up the work area if you need a lot of them.
All the best:Earl
07-22-2001, 12:48 PM
I would like to carry the adage about not bolting if you can screw and not screwing if you can nail a step further. If it ain't broke, don't fix it. It sounds like your fastenings are fine so why do the inevitable damage to the frames by refastening. The tenail idea is fine but your frames are far to small for trenails. Since your boat is a Canadian gillnetter it was probably insured by Mutual Marine (virtually all fishboats are)they require you to remove a few fastenings every couple of years. They like you to do it near the batteries and obviously underwater. Check your bungs in that area and you may find some are red lead instead of plugs. If not, that is the place to inspect your nails (which by the way are proper boat nails and readily available in B.C. Try Western Marine in Vancouver or e-mail me)Use a proper nail pulling tool. They will come out. If you are still nervous about the fastings then bolt the butts which is amost certainly already done but you could start redoing. My own boat is fastened with boat nails into oak frames and is 101 years old. I have never found 'nail sickness' where there wasn't some other damage. Hope this helps, firstname.lastname@example.org
PS I'm not that excited about spraying your boat with fresh water all summer long. Talk about asking the devil to sup.
07-24-2001, 12:37 AM
Here's the plan. Stop the sprinkler now and next April we'll have a bonfire. Then we'll sell the scraps and take the Triumph out instead. Alright, maybe I'm just boatsick.
Good luck, I can tell it's going to be fun and we both wish we were there to see it,
Eli and Sarah
07-25-2001, 01:02 AM
Sarah and Eli, got your message but its no deal - you have to come back so that Sarah can do the painting on Penta this fall cause the Triumphs are all out of service !!
Miss you guys!
07-26-2001, 12:05 AM
Okay, but seriously, what about 'Gairlandizing' with the router and rivets? You could do the temporary bolt thing to suck things tight and then fill any extra holes a la Robb White, with a hot rod and epoxy to make the filler bungs permanent.
07-26-2001, 08:48 AM
Is this a Victoria reunion?
How's things "boatless"-people?
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