Pulling Stitches

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....


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RE: Pulling Stitches

 I hate auto-spell-correct....

 

RE: Pulling Stitches

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

RE: Pulling Stitches

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   

RE: Pulling Stitches

Hokker, you're referring to Gramps' lighter idea? I'll try that first before messing with my battery brainstorm, thanks to you both!

RE: Pulling Stitches

áááYes, I used my old Wen solder gun and it works fine. Yes, you can still find tips for them.

RE: Pulling Stitches

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

 

RE: Pulling Stitches

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....

RE: Pulling Stitches

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….

   

RE: Pulling Stitches

   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.

RE: Pulling Stitches

áááConsider 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

RE: Pulling Stitches

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

RE: Pulling Stitches

áááOn 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.

RE: Pulling Stitches

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

 

RE: Pulling Stitches

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?

RE: Pulling Stitches

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!

 

 

 

 

 

RE: Pulling Stitches

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

 

RE: Pulling Stitches

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?

RE: Pulling Stitches

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

 

 

 

RE: Pulling Stitches

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.)

RE: Pulling Stitches

áááI think I'll just tack between the stitches, seems way less complicated, I'm not in a race. I sure know what to do if I gob over a stitch or two! Thanks for this thread!

RE: Pulling Stitches

   Ok, I'm new to this process, and this thread has left me a bit verklempt (let me catch me breath, talk amongst yourselves for a moment).

I'm building a cocktail racer, and the instructions say to leave stitches entombed in epoxy until the end of time. The stitches along the bottom came out, as they were between the welds, but the rest are radiating their anti-tennis elbow magic from inside the fillets.

Am I doing something wrong?

 

 

 

RE: Pulling Stitches

Perhaps the authors of the manual thought to help you maintain your boat in good humor long term...by keeping it in stitches!  <;-)

Sorry for the punnery.  Seriously, it's probably a case of "different ships, different long splices", you think?

On the one hand, one might worry about leaving the nipped-off stitches in to expand and contract at a different rate than the wood and epoxy in which they are embedded, perhaps getting up devilment by letting water get into the plywood and causing damage you won't notice until it's advanced?  Who knows?

On the other hand, there are a lot of stitches to pull, so why not just nip 'em off flush and leave 'em?  The whole business is going to get more epoxy, anyway, and the little dot where the wire got nipped off (hopefully flush) probably won't look any worse than a filled hole where the wire was pulled and filled with epoxy, so does it matter?

On the third hand...oh, wait, we're out of hands...Evolution has not yet provided humankind with what I personally think would be a most useful physiological improvement: a third arm with a third hand, possibly double-jointed so it could grip left or right handed!  Seriously, how many times have you been in a situation where a well behaved third hand with decent reach might have seemed a life saver?  So, why haven't we evolved one by now?  I mean, it would give your shirt maker fits, no doubt, but maybe a three armed shirt maker might not think it much trouble, seein' as he's got three hands to work with his own self.  But, I digress....

Anyway, you see my point.  We can make ourselves crazy puzzling over such details, worrying that we'll make some irresoluble mistake, when the truth is that it's epoxy and plywood and, short of gluing the thing up so it's noticeably crooked, there really isn't much that can't be passably rectified by a patient amateur or even a complete novice, especially if the finish is to be paint instead of varnish.

Just to be sure of it, I grabbed our PMD builders' manual (version 3.5, July, 2011) just to double check what it said versus my memory of what we did with the stitches.  My memory was that that we glued entire seams (with the "mustard" epoxy and silica, not the "peanut butter" epoxy and wood flour) at one go, i.e, not "tack welded", and pulled the stitches after the epoxy had cured, heating a wire end with a a long necked butane lighter to loosen 'em up as needed.  We then went around with wood flour thickened epoxy to fill in the holes and any other remaining irregularities.  This is pretty what the manual described on pages 48 and 49, though the accompanying photo of the butane lighter business shows somebody with a regular cigarette lighter in hand fixin' to burn his thumb.  We had better sense than to emulate that detail!

The instructions for the transoms on pages 40 and 41 are different. It shows the transoms wired into place with the twists on the inside, then "tack welding" with wood flour thickened epoxy, then, once that cures, "gently snip the wires holding the transoms in place."  It doesn't explicitly say "snip and pull" the wires, but I seem to remember that's what we did, more or less, which makes sense.

Anyway, your Cocktail Racer (or the original Waterlust in this thread) might be entirely different, for good reasons, compared to what we did five years ago for our PMD based on an eight year old manual.  My advice?  Follow your manual.  If something is unclear, or just doesn't make sense to the point where you think you might not understand correctly, give CLC a call before proceeding.  They're always glad to hear from builders.

.....Michael

RE: Pulling Stitches

RiccardoL,

As Michael says, follow the manual. Except for when you don't. And when you don't, have a good reason not to and know what you're doing. If you don't know why and what you're doing, follow the manual.

If you have to ask, follow the manual. Very clever people have worked out a sequence of operations that will succeed. CLC depends on customer goodwill. If you have a sucky building experience, you won't come back, you'll tell your friends and they won't come, either, and John Harris will have to live off of what people will put in his hat as he plays Stairway to Heaven on his trombone at the subway entrance. So you can bet that following the manual will yield a great boat.

Once you have some experience under your belt, then you'll be able to consider riffing on the manual. Just like a good jazz player, you can't improvise until you can play it straight, transpose it, etc. And, just like a good jazz player, just because you can improvise doesn't mean you should. The musician has to have something to say with that riff and the boat builder needs to have a reason to deviate from the manual.

In my case with pulling the stitches, I have definite goals that I've come up with and I'm willing to go to the extra trouble and take more time to achieve them. I'm also willing to accept the risk and not blame CLC if it fails. After all, they included a perfectly good manual.

So while I prefer tacking and pulling the stitches, and I think that's the best way to go, that's for me. Others should make their own decisions. Following the manual is never a wrong decision.

Have fun,

Laszlo

 

RE: Pulling Stitches

   FWIW: Vice Grips = third hand

RE: Pulling Stitches

Catboater suggested: "Vice Grips = third hand"

Well they do have a place in my toolkit but I'd have to wonder how employing a pair for pulling stitch'n'glue wire stitches would free up my other two hands? For what I've done so far it seems two hands is enough: one to hold the heater, t'other to hold pliers, of whatever style. I use linemans' pliers sometimes, needle-nose others.

As for heat? Stopped by local Menard's a couple days ago for some foam rollers (at the suggestion of Bob Santore elsewhere here) when I spied one of those fuel-filled piezo ignition lighter gizmos, this one touting "wind proof" torch-like flame.

I dismissed the suggestion earlier on, owing to the experiences I'd had with similar products before for lighting candles & such; more convenient than a simple match but lacking in anything special otherwise.

This new thing is impressive! Visible flame's maybe 3/4" long & about 3/16" dia. at the device's tip but holy mackerel it'll light a candle wick in an instant with the nozzle held 2" away! Sounds like a mini-blowtorch & behaves like one on a small scale! Bonus is it's refillable using fairly commonplace butane lighter refills. I'll be trying this thing for stitch-pulling the next time I'm doing that operation.

Pretty impressive at a $1.99 price point at Menard's - SKU #'s 6408108

RE: Pulling Stitches

   Here's an enthusiastic endorsement for spclark's approach to using a soldering gun to expedite pulling stitches.  Searched this forum after pulling a few with a soldering iron to soften epoxy and calculating how many hours it would take - MANY!

He suggests #4 copper.  I got a foot of  #4 and #6 (free when the clerk couldn't figure out how to charge me... Lowe's) and the #4 was clearly to large.  #6 took a little tapping on the anvil to taper it 'til it fit.

Worked like a charm!  Seconds per pull:  https://youtu.be/Pi6tlPZhcts

 

RE: Pulling Stitches

   Correction:  that's #8 wire in my setup

-Andrew

RE: Pulling Stitches

   Like everything else working with epoxy, neatness goes along way. I used a plastic ketchup bottle from the dollar store to tack my hull with thickened epoxy. I never got near a wire on my SW Dory and just pulled the wires out. No heat needed.

RE: Pulling Stitches

I agree, neatness is a useful attribute when dealing with epoxy. Still, there may be times when it's aparent that simply tacking seams isn't going to be enough, or you wish to fillet over wire stitching for a particular operation.

What I subsequently learned by experience after I initiated this thread almost 2-1/2 years ago is that simply putting a couple of large-diameter copper wire in the soldering gun's tip holders, then touching one each to the ends of a stitch left long enough while the gun is energized, causes the stitch wire itself heat quite rapidly, weakening the surrounding epoxy sufficient that pliers will then pull the wire stitch free in seconds.

A useful technique when necessary, certainly faster that waiting for heat from a soldering gun to propagate along a stich wire prior to its being pulled free.

And best not inhaling the smoke from burned epoxy that can result from leaving the gun tips in contact with a stitch for too long. 

 

RE: Pulling Stitches

   The efficacy and neatness of tacking notwithstanding, I'm a first time boatbuilder and followed the instructions (think of that!),  which led to fillets entombing wire stitches.  Then I realized pulling them was a possibility and got out the soldering iron...  SLOW!  Then I discovered this thread:  FAST AND EASY!  Thanks!  A lot quicker & neater than cutting wires flush and sanding those that protrude (per manual).

Thanks for all the great tips.  Next time (if there is one) I'll see about tacking.   I think I just figured out the CLC marketing model (aside from the great boats) - when you've built one of these rascals you've learned so much that you have to do another so the learning doesn't go to waste!  And the cycle repeats!

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