Bulging 2nd Planks

[drjeckl]

I'm about halfway through 2nd planking my Lady Nelson, my first build.  Started at the bulwarks, working down toward the keel.  Halfway down and now starting at the keel and working up.  I use CA for this.  I start at the bow; apply about 1/2 inch of CA and hold down the plank for about a minute, tight to the hull and against the plank above.  Then use a glue looper to get under the loose section of the plank and spread about an inch more of CA and hold down that section.  Repeat until I get to the stern end.  Been working pretty good so far:

 

However, as I am waiting for a plank at the keel to dry out after form-fitting it, I'm noticing that a few of the installed 2nd planks, in certain spots, are 'bulging' out; i.e. I can press on them and they move in tighter to the hull.  Here are 2 photos of an example.  The difference is only slightly noticeable and I've notated an area that you can see the difference:

 

 

So the obvious questions are:

1. Is this a problem I should be worrying about?  I'm willing to put in the work to rectify this if necessary.  I've installed half the planks so far and there are only about 4 or 5 bulging spots so far.  But do I need to fix this?
2. If I should fix this (I think I should), what's the best technique?  I could brush in some diluted PVA where the bulges are but how do I hold down those areas while the PVA sets where I can't get clamps to work?   I've seen some people use rubber bands with erasers holding down planks while the glue sets.  I may try that.  Any other thoughts?
3. Should I tweak my gluing process?  I'm not really getting CA on the edges of the planks.  From what I've read, that is not absolutly necessary.  If it is, how would this be done?  Any other tweaks?  I'm comfortable using CA and would not like to switch to PVA.

 

Thanks...John

[Roger Pellett]

The curves defining ships’ hulls are supposed to be what Naval Architects call “fair,” smooth without lumps or bumps.

 

If you bend a strip of wood without restraining it, it will automatically assume a fair shape.  

 

If localized areas of your planking are pulling away from the substrate it is probably because your “first planking” has not been properly faired.  Trying to correct this by injecting glue and squeezing more glue underneath will only cause areas of unfairness in your finished hull.

 

Roger

[drjeckl]

22 hours ago, Roger Pellett said:

If localized areas of your planking are pulling away from the substrate it is probably because your “first planking” has not been properly faired.

Maybe I didn't make my point sufficiently enough.  The bulge is quite infinitesimal.  And I pre-bent the planks to fit the form of the first planking before gluing.  I believe that my glueing of some of the second planks missed some spots and I'm trying to fix that.

 

John

[glbarlow]

Hard to say, haven’t encountered that. I put little dabs of CA, don’t need much, along the whole plank. I leave only a small space between each dab, no big gaps along the way.  It’s also important to have the right bends in the plank both in and down using Chuck’s method.  You’re right, no edge gluing is needed. So the only thing I can guess is your gaps between CA are too large or the bend isn’t right or a combination of both.  
 

Your first planking needs to be very smooth and faired. You can’t get a different hull with the second planking, it conforms to the first.   

Edited January 19, 2021 by glbarlow

[drjeckl]

1. If I should fix this (I think I should), what's the best technique?  I could brush in some diluted PVA where the bulges are but how do I hold down those areas while the PVA sets where I can't get clamps to work?   I've seen some people use rubber bands with erasers holding down planks while the glue sets.  I may try that.  Any other thoughts?

[VTHokiEE]

24 minutes ago, drjeckl said:

Any other thoughts?

When all else fails I have at times resorted to my 2 five finger clamps and distract myself for a little while until the glue sets.

[drjeckl]

But is brushing diluted PVA where the bulges are the best method for these bulges?

[Snug Harbor Johnny]

It looks like there are a few 'low spots' in the first planking. Fixing that before going further should help.  I've used 'one minute' epoxy in the past (this was before CA was available, and I had to be quick mixing and applying) and held a plank in place using the long fingers of both hands ... and half-listening, half-watching the TV while the 'set' of the bonding agent firmed.  Still, the quality of the fairing will determine the quality of the final planking.

[Louie da fly]

Yes, when no other clamps will do the job, the "Five finger" clamps and a little patience (reading, watching tv) seem to work best. Having got to the stage where nothing else works, not even my tiny clothespegs, I'm currently using that technique on the planking of the longboat for my Henry Grace a Dieu, where the planks join the stem and sternposts. Time consuming, but it works.

 

Steven

Edited January 20, 2021 by Louie da fly

[drjeckl]

On 1/20/2021 at 4:11 PM, drjeckl said:

But is brushing diluted PVA where the bulges are the best method for these bulges?

 

[Nirvana]

Apply PVA in-between the bulging area (not to much), let air dry for a minute.
Don't touch it during the time... you can wait another half minute if you like to.

Now here is the trick, use a warm (not burning) iron and move over the area you want to "seal".

If you done this right the heat will create a bond that is really hard, and not bulge.
Try on separate piece before to find your best outcome.

This has worked for me. Good luck.  

[drjeckl]

Nirvana,

 

Thanks for advice.  One question:  Use PVA out of the bottle, or diluted?  If diluted, to what ratio?  Will undiluted wick into the bulge enough?  And presumably, use white PVA, not yellow?

 

Thanks...John

[Nirvana]

Apply directly from bottle but thin, not diluted.

That's how I attached the cap rail on my longboat. 

[drjeckl]

Thanks.