Approaching the time when I'll begin pulling sticthes on my Waterlust project, a thought struck me yesterday that I'd like to put to other builders -
Frequently suggested is using a soldering gun (not a pencil or, heaven forbid a torch!) to apply heat to the stiching wires so as to soften the grip of epoxy that would otherwise make them dearly impossible to remove.
I haven't quite gotten to this stage but being of a mind to think past potential pitfalls - as in the wires not being heated far enough into the epoxy to loosen it while the end being heated begins to char the plywood - has anyone tried briefly 'shorting' a 6 or 9v battery across the two ends of a sticth so that the wire heats more evenly from both ends? Taking the concept further one could attach one pole of the battery to the pliers being used to pull stitches, the other pole having a heavier-than-stitching wire attached to the other end of the stitch with an alligator clip, so that as heat builds the pliers could be used to apply tension? Once the stich is loosened enough, it ought to slide out quite easily, yes?
I have a (decades old Wen; can one still find replacement tips for these antiques?) soldering gun I'll be using shortly as suggested by many, but may try my concept method too then report the results....
I hate auto-spell-correct....
We used long-necked butane lighters. Heat one end of the wire (flame not pointed toward the boat) while pulling on the other end gently with pliers until the wire slides out. Doesn't take but a couple of seconds, and no harm to the boat if done quickly and carefully.
.....Michael
That's exactly what we did when I started my Skerry build in a class at CLC. Worked like a charm, and absolutely no damage to the boat itself.
hokker
Hokker, you're referring to Gramps' lighter idea? I'll try that first before messing with my battery brainstorm, thanks to you both!
Yes, I used my old Wen solder gun and it works fine. Yes, you can still find tips for them.
1. Copper conducts heat much much better than wood.
2. Epoxy loses its grip at around 140 degrees
3. Wood start charring at a bit over 400 degrees.
Putting all that together, the epoxy around the wire gets soft enough to release the wire long before the wood get hot enough to char.
I used a standard soldering iron (for electrical work, not plumbing) and the technique that Gramps described. I bought it earlier this year at Home Despot, nothing special.
Personally, I like the soldering iron better than anything with an open flame, not to avoid burning the wood, but because of sawdust, thinners and other flammables in the shop.
Laszlo
Tried WEN, works OK. Needs new tip (found idea for making 'em from heavy solid copper wire, will try that after work tomorrow.)
Tried long-stemmed butane-fed 'lighter'. Worked but just for two stitches, then ran outa fuel. As with Lazlo I'd prefer a flameless technique over open flame.
Will try my battery idea after work tomorrow, or Sunday.
Stay tuned....
So the battery idea proved to be a waste of time Nothing short of a 12v lead-acid provides enough amps to heat the 18 ga. copper wires quickly enough.
Not wanting to go the long-stemmed lighter route I went back to my venerable WEN.
Then the tip it’s worn for maybe 40 years gave out.
So while searching the ‘web for sources to order up new tips I ran across a forum somewhere with a post about making your own from a length of solid copper wire.
So tried that. Bought two feet of #6 copper (0.061” dia.) 8" of which proved to offer insufficient resistance to heat up much. Soldering gun sure heats up though! So it’s apparent those tips are designed to offer resistance sufficient to melt solder….
Tried 12 ga. bare copper. Pretty much same result though it did get hot enough to pull a couple of stitches.
Then inspiration dawned!
I went back to the STIFF 6 ga., cut two pieces about three inches long, secured each in the sockets on that WEN.
You can bend the two wires into a Y shape, or a wider V, or put ‘em parallel anywhere from 1/4” to an inch or more apart. Held so that each #6 wire touches opposite sides of a stitch, when you pull the gun’s trigger that stitch gets HOT in an instant!
The battery idea started with the thought of making the stitch part of a circuit rather than just something you apply heat to. This new idea of using the soldering gun as a current source does exactly that! Stitch wire’s heated its entire length, pulls out super fast!
I pulled fifteen+ stitches this way in the time it took me to pull two with the stock tip in that WEN before the tip died.
Maybe posting this here will help others achieve similar results in overcoming the frustration of a task that takes way too long….
Diverging on this topic. I've built a NE Dory and 2 kayaks, and yes, I've had to heat several stitches with the soldering iron to pull them. No big deal. As often as not, I've found a good strong pull with good fencing pliers would free (lightly - not buried in epoxy) stuck stitches, sometimes even using a thin piece of scrap wood for protection of the boat's wood and levering out the stitch. Fencing pliers have a "rocker" shaped head and are desinged for levering out fencing staples. You hear a "snap" when the epoxy lets go and out comes the stitch, no time spent heating. And if the stitch happens to break, you can usually then take the time to heat it and pull the other end. All this helps things go faster than heating every stuck stitch.
But the point of my posting: Even more for the purpose of making smoother joints and filets, I've found it (as often as possible) much preferable to tack weld only in the areas between stitches, often with CA glue instead of epoxy. Then pull stitches, then to make the joint with a nice smooth continuous bead of epoxy (at this point with a tack-welded structure you can also usually "roll" the boat to position the joint for most beneficial flow of the epoxy into the joint without drips. And using clear packing tape pressed well into the seam crease on the oposite side of the seam just for long enough to allow the epoxy to soft-set also helps avoid drips. If you take the time to watch for the epoxy to soft-set, you can even pull the packing tape and smooth the glued seam with the alcohol-wet (gloved) finder smoothing trick. Then put in nice smooth filets. As noted in many other hints, techniques and places - if you REALLY want to save some time, minimizw the amount of time you need to spend chiseling, scraping, sanding and otherwise smoothing hardened epoxy!
When I first started I did a joint or two by epoxying the entire seam without tack welding, gluing stitches in place, snipping ends and fileting over the stitches. The stitches left little bright dots in the finished piece where the sanded ends showed through the finish, and the filets were hard to smooth due to the interference between the wire and the radiused filet tool. I'll never do joints that way again.
Bottom line, certainly this thread on how to pull stuck stitches is interesting and valuable. Maybe even more valuable is stressing the idea that tack welding and avoiding stuck stitches has several benefits, perhaps least of which is not having to pull stuck stitches.
Consider that the old solder gun is really just a transformer power supply to put a voltage across the tip with the right resistance and you’ll see why the trick of putting 2 ends to a stitch will both work and be a bit chancy. For new tips see McMaster:
Https://www.mcmaster.com/soldering-irons
Dang, I hadn't heard of the tack welding thing. Interesting. Described here in CLC's description for the glue they sell:
https://www.clcboats.com/shop/products/boat-building-supplies-epoxy-fiberglass-plywood/ez-bond-ca-glue-cyanoacrylate-adhesive-medium-viscosity-2oz.html
Now, who's gonna remind me about this if I ever go to build another CLC kit? <;-)
.....Michael
First, a nit to pick. Welding is melting 2 pieces of material with heat or chemicals so that they flow together and bond when they re-solidify. So to be tack-welding the seams you'd need to be applying a wood solvent that evaporates and lets the wood reharden, or enough heat to melt the wood so it will flow. Since neither of these is happening, or even possible, "welding" is not what this is. How about we call it "tacking"?
End of pedantry.
Tacking between stitches with epoxy is very effective and makes for the thinnest and lightest seams possible. It's also strong enough to use on even relatively large and heavy boats. That's how I attached the one-piece bottom (1/2" plywood, 18 feet long) to the sides (1/4" plywood) on my 18-foot schooner. It was a strong enough attachment to allow me to lift and move the boat after the stitches were pulled and before the fillets were laid. If it could handle that, it should work on any of CLC's designs.
Tacking with epoxy/woodflour putty also eliminates any compatibility problems between the tacks and the fillets. The only caution is that you need to make sure that the tacks are fully cured before removing the stitches. In normal temperatures, a 2-3 day wait guarantees this. This is also a good use for fast hardener. That can shave a full day off the wait from slow.
Have fun,
Laszlo
On my skerry, I did spaced epoxy fillets between the stitches per the manual. Not as fast as CA gluebut still let’s you pull stitches easier then go back over with full fillets. Won’t work for all joints but it did speed up the removal process.
I'm about to pull stitches too. What about a heat gun? Would that soften the epoxy sufficiently to allow the wire to be pulled out?
Geophile asks: "What about a heat gun?"
No, not something I would recommend! A heat gun is too "unfocused" if you will...
My entire 'mission of discovery' prompting this thread was to come up with a means to heat just the wire stitch in a manner I felt more uniform from one end to another than a soldering gun appears to do.
Using a heat gun (I have one, 40+ years old from my days of making laminate-covered furniture and cabinetry) to perform this operation is just too broad a brush. The heat applied to your project's plywood components may well serve to soften the epoxy you've so patiently waited to cure. In fact this tool has been recommended for disassembling puzzle joints that have gone together in an unsatisfactory fashion for just this attribute.
Here's a pic of what I see when I've set up my soldering gun as described in an earlier thread. If you're using a similar gun, but fitted with a proper soldering tip, you'll use the glowing red-hot end to heat one end of the stitch enough that the epoxy holding it in place softens enough to allow the stitch to be pulled.
Problem with this is if the stitch is long and/or the epoxy covers a significant length the heat applied at one end may not soften the epoxy at the other end enough before the plywood begins to char near the soldering tip.
My 'modified' gun approach circumvents this by making the stitch the heating element. You merely touch both ends of the heavy copper wires that replace the conventional tip to each end of the stitch long enough to soften the epoxy - it takes only a second or two - then pull with pliers.
If you're not comfortable with this method by all means don't bother trying it. But it does work and in a manner similar to using a standard, un-modified soldering gun for this process, just considerably faster.
I've learned a lot from the responses my original post has inspired. Further progress on my Waterlust project will surely benefit! Thanks all!
spclark's setup:
Definitely use ventilation/respirators, epoxy smoke is not a good substitute for air.
What do you use when one side of the stitch has broken off flush with the wood?
Laszlo
That pic had me juggling my phone and the transformer so it went a little longer than normal, hence the smoke.
True enough one needs to avoid breathing smoke from this (or any!) kind of operation. With practice it's easy enough to judge when a stitch is heated enough that a gentle tug will pull it free before I see that telltale plume.
Broken ends I try to avoid. If it happens anyway I'll just cut off the other end & live with it. Not aiming for a 'bright' finish so they won't show. Avoiding entrapped stiches in the first place - so this whole procedure is unnecessary - I view a 'best practice' as they then can be clipped on the inside then pulled from the outside, leaving no sign they'd been there but a couple of small holes and far less chance an end will break off.
Thnx for moving my image to the fore. I'm no coder, other forums pose less of a challenge... my apologies if my use of Dropbox is intrusive somehow.
I've looked at what the little pic and question mark buttons offer (extreme right above message-entry window) but the former leaves me clueless as to what gets entered where and the latter ends in a 404 Error - Page Not Found when I click on the link it brings up hoping to find something useful in the CKEditor User's Guide.
Laszlo what hosting service do you use? Free of charge or pay-to-play?
As far as I know, nobody objects to you linking to Dropbox. I inserted your picture in the post purely for convenience, so that your setup would be visible in the same window/tab as your descriptive text.
To do that, I followed your link to Dropbox, right-clicked on the picture there and copied the image location. It's a really messy URL, but I tested it by pasting it into the URL box in a new browser tab and got your picture, so I knew it would work.
Then I pressed the "little pic button" you mentioned and pasted the URL I copied from Dropbox into the URL field. Then I tested it by clicking into the Width field. The Width and Height numbers came up and the Preview box showed the picture, so I hit OK. No coding needed.
I host my images myself on my own domain server. The hosting is free (to me), but I have to pay for the server, so call it whaterver you want :-)
Laszlo
Thanks for the lesson! I'll try that next time I have an image worth sharing. Enjoy your holiday! (I'll be finishing up my Harken Hoist installation once the dead bird's in for a sauna.)
