Do I need to fill the stitch holes?

I just finished my first coat of epoxy on the hull of my Passagemaker and noticed I can still see through some of the stitch holes.  Should I have filled them or will they fill up as I add more coats of epoxy.  What do others do?  I can’t see any recommendation on this in the manual. 


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RE: Do I need to fill the stitch holes?

   On my earlier boats I didn't fill holes, and occasionally suffered some drip-thru runs (during construction), or see thru tranparent "holes" - only obvious from up close (after completion).

On later builds I took to simply walking around the boat with a little tub of wood filler (easier to sand than self-made epoxy/wood flour mix) and a small putty knife.  Dab on a bit with fingertip, trying to push gunk well into hole, swipe over it with a putty knive and on to the next hole. You can probably do every hole in a kayak in less than 20 minutes, and by the time you are done filling the last hole, the first hole you did is probably dry enough to swipe over lightly with some 120 grit sandpaper.  Then ready to proceed with epoxy or glass coating.

So, for something like an additional hour of build time, the holes can be made almost abolutley invisible.  Trying to shave off/sand away one hardened epoxy drip-thru that can happen while glassing probably takes almost as much time, so I consider pre-filling the stitch holes as time well spent.

Now that you've already done one coat of epaxy the fix might be alittle more difficult - but if you actually have a real pass-thru hole still there now after your first coat of epoxy, maybe some filler is in order.  But seeing as you wouldn't be using wood putty on raw wood, in this case I think you'd better go with an epoxy/wood flour filler.  Blade the fill off very smooth after fillling, as sanding will be more difficult.

RE: Do I need to fill the stitch holes?

  If you intend to paint the boat (inside or outside, does not really matter), the holes might show through primer and paint, in case they remain unfilled. At least that's what happened with my Chester Yawl build: after I thought I had them filled properly, I applied primer - and then they showed up anyway. I ended up sanding off 30% of the primer, putting on small heaps of wood flour thickened epoxy on each unfilled hole, sanding those down again, and have yet to apply unthickened epoxy, and primer on top again... That was quite frustrating. So I think it's worth the effort to make sure the holes are properly filled. I'd follow Bubblehead's recommendation.

RE: Do I need to fill the stitch holes?

Not the answer I wanted to hear at this stage in the game.  I should have thought about this sooner.  I think the wood filler before you start the epoxy first coat is the way to go!  It would help if that was in the book.  I just thought the epoxy would fill them without an issue but it doesn't.  So now I have 3 coats of epoxy on.  Arrrg, I think I will walk around the boat with a drill and drill out any holes that are not covered with epoxy and fill them with epoxy wood flower mix.  Most of the holes in the bottom of the boat are filled with epoxy but the ones on the side are not allowing the epoxy to flow into them.

 

Thanks!

RE: Do I need to fill the stitch holes?

As long as the holes don't leak, they're no problem. From a visual perspective, I take the point of view that they're the same as stitches on skin and frame, the rivet heads on steel ships, the beads on welded metal vessels, the plank seams on clinker built, etc. They're the natural artifact of the construction method. The only styles of construction that are Inaturally smooth are the ones that come out of molds. I don't believe in the idea that I should go to all the trouble of making a superior looking and handling lightweight boat and then try to make it resemble a roto-molded clorox bottle plastic job by hiding the stitch holes, but that's me.

That said, as the builders we have the ultimate freedom to do what we want. If you really need to hide the holes, or need to fill them to stop leaks, there's an easier and stronger way than puttys - toothpicks. A round tapered toothpick can be pushed into a hole once the wire is pulled. Dip it in epoxy or waterproof carpenter's glue and push it through until it stops. When the glue has set, cut it off with a razor and you're ready for sanding.

If you've already epoxy coated the boat, I'd recommend a stiff mix of epoxy and phenolic microballoons. That'll fill at least as well as wood dough, is much easier to sand than epoxy/woodflour and is guaranteed compatible with the epoxy already on the boat. Depending on your primer, it could also be compatible and let you fill things in without removing the primer first. System 3 Yacht Primer is one such.

Finally, you can avoid a lot of this by not leaving any bare wood. A layer of 4 oz cloth adds very little weight overall (about 1/2 a pound per square yard when completely finished), provides excellent abrasion protection and makes sure that the holes are filled in with no leaks or dimples. They'll still be visible with a varnish finish, though, so you may need the toothpicks if they bother you.

Have fun,

Laszlo

 

RE: Do I need to fill the stitch holes?

One more thought

Since I’m drilling out the stitch holes (with a 1/16 bit) carefully by hand.  I wonder if I can just use wood filler?  I was going to put another two layers of epoxy down anyway.  I think wood filler will work as I’m exposing wood inside the hole with the drill.  This way I can pick a wood filler color closer to the Okoume’s color than the epoxy wood flower color is.  This may make the holes disappear on the outside.  

Thoughts?

   

RE: Do I need to fill the stitch holes?

 

@Laszlo

I love the toothpick idea!  I could just dip them in epoxy and push them in.  

I also agree with your statement that the holes are part of the construction process and not a big deal.  I knew they would be visible that really wasn’t my concern.  Spending 6 plus weeks to build a boat and have it leak the first time I put it in the water is not a lesson I want to learn the hard way!   

Let me know your thoughts on the wood filler.  If it is going to be a problem at this stage (I have 3 coats of epoxy already on and planning on adding two more coats) I think I will go the toothpick route.

RE: Do I need to fill the stitch holes?

I don't know about wood filler, I've never used it for S&G boats. Bubblehead has a lot more experirnce with it than me.

My main concern with it is long-term stability. Does it bond well enough to epoxy-coated wood to stay in place for years? Will it expand and contract at different rates than wood when the temperature changes and eventually pop out? Or does covering it with epoxy stabilize it in place and solve all these concerns? Maybe Bubblehead can tell us how it worked out for him, how many years has it been and recommend some brands.

Laszlo

RE: Do I need to fill the stitch holes?

   Wood Filler?........you mean sanding dust mixed with epoxy or carpenter's glue?  Yes, that would work since it will be encapsulated. Sanding dust will be just a little darker than the wood it came from.   But wood filler you buy at the hardware store and comes in a can, no.  We're better than that.  The problems my neighbor comes up with for me to consolt on usually has wood filler in the description of the failure.  Besides you don't know what kind of additives they put in that stuff and if it is compatable.

Besides 99% of the people inspecting your boat won't even see a stitch hole after its built.  I left the wires in my Cheasapeake. I have to point it out to people. They don't see detail. They don't see scratches. They just see the overall boat. 

Now if you want to focus about detail, OK. But you will have plenty of joints, wiggly coves, oversanded edges/layers, etc to grieve about. 

RE: Do I need to fill the stitch holes?

All great advice!  I went the toothpick route (or should I say treenail).  I used a 1/16" bit to drill out all the exposed holes.  I was careful to not drill all the way through when there was an epoxy fillet or fiberglass on the other side.  I then fitted each treenail into place before I mixed up the epoxy.  Once all treenails were fitted into place, I mixed a one squirt batch of epoxy.  I dipped each treenail in it and placed it back in the hole.  Once they were all epoxied in I lightly tapped on each one with a small hammer.  I then clipped them off with my wire cutters and wiped up the excess epoxy so I wouldn’t have a sanding nightmare.  The whole process ~250 holes took about 4 hours.  I’m looking forward to sanding them off tomorrow morning.  I think the contrasting wood colors are going to be interesting.

RE: Do I need to fill the stitch holes?

   One more Pic.  (wish you could edit your previous posts)

RE: Do I need to fill the stitch holes?

   One more Pic.  (wish you could edit your previous posts)

RE: Do I need to fill the stitch holes?

Can't see any of the pictures. icloud is saying I'm unauthorized.

RE: Do I need to fill the stitch holes?

 

Trying pics one more time.  Here is the web site if that works

RE: Do I need to fill the stitch holes?

Pictures didn't work (it can be a tricky business, no worries) but the link did.  Nice work!

I'm trying to remember what we did with the holes when we built our PMD back in 2014.  I remember heating the wires with a long necked butane lighter and pulling them out, but hang me for a pirate if I remember how we ended up stopping up the holes.  Whatever we did, they never came back to haunt us as leaks and the results are now underneath the paint.

We'd have painted the boat rather than varnished, never mind the wire holes.  I'm not a big fan of the look of varnished plywood, a matter of taste.  "Different ships, different long splices...."

We wish you all joy of messing about in your fine looking boat!

.....Michael

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