2nd layer of hull plank installation question

[acaron41120]

I'm getting ready to start the 2nd layer of hull planking. I've triple check the sanded hull with eye, thin plank and cardboard and I'm seeing no peak or valleys. With the first layer of hull planking I used tick steps and divided the hull into 4 areas and used the method in the tutorial. (works great by the way). So my question is do I need to follow that same procedure (tick strips etc.) for the 2nd layer of planks? 

[allanyed]

Allen,

I can think of no reason why it would be a bad idea to not use the same methodology.    

Allan

[mtaylor]

I agree with Allan but say that it should be checked and re-marked.  The reason is the first planking adds to "volume" of the hull slightly and you may need one plank for maybe two depending on the thickness of the first layer.  Better to know before laying planks than later finding during the planking.

[acaron41120]

Okay thanks for the replies. I kind of thought I was going to have to line it all again. My major difficulty with planking the hull (whether the 1st or 2nd layer) is the Garboard Strake. For some reason the devil lives in that strake.

[allanyed]

If you look at the shape of the garboard strake on a plank expansion plan it may help you to shape the strake.  While it tapers along its length in some cases, the key is for the forward end not to go too far up the rabbet at the stem.  One example is https://www.rmg.co.uk/collections/objects/rmgc-object-83495  The upper is the ceiling planking and the lower is the hull planking.

Allan

[acaron41120]

Well I started the garboard strake dry fit and just didn't like a portion of the port side of the hull. Just seemed not quite right. So I sanded the area and then the whole hull again with 220 grit sand paper. Looks better now but I still wonder if I should sand it one more time but with 400 grit this time. Then install the second layer. How many times do you experienced folks sand the hull? I started with 100 grit, then 220 and now will do my final sanding with 400. THEN...after the second layer of hull planks are installed, start sanding lightly with 400 and 1000. Does that sound about right? The bottom half of the hull will be painted flat white and the upper portion will be stained mahogany.

[mikiek]

As stated, be sure to recalculate the next layer. Don't try to follow the lay of the previous layer.

 

The garboards should go in straight - no bending. Yes there will be a lot of twisting and turning but no bending. If you find that it is wanting to bend up at the bow most likely it is pushed too far forward. You should be able to lay the next strake on the top edge of the garboard and it should sit flush. I usually try to pin the garboard in place then lay the next strake on top just to see how the two will mesh. Then adjust and glue the GB.

 

If the GB is bending all subsequent sticks will want to bend as well.

 

Another thing you can do is take the stick that will be your GB and put the bow end into your rabbet about midship. Lay as much of the edge in the rabbet towards the stern. Then start sliding the stick forwards in the rabbet toward the bow keeping a close eye on that leading end. You will either see the stick start to move upwards when it gets to the stem or it may just stop and not slide anymore. That's where it should lay. You can then do whatever shaping you need to do to the front end of the stick.

[allanyed]

9 hours ago, mikiek said:

The garboards should go in straight - no bending.

Practically speaking, this is true, but as the keel tapers from midships both fore and aft, there is slight bending but not really enough to cause much aggravation.  I may off base on this , but it seems most kits forgot to include the taper so it not a factor anyway.   Just as an FYI, the taper varied slightly with time and maybe nationality.  This example is from the 1719 RN Establishment - The width for a keel about 90 feet long would be  12" midships, 10.5" wide forward and 7.5" wide at the sternpost.   For the Mayflower, if these were close dimensions of her keel,  at a scale of 1:60 this would be about 0.2" (5mm) at midships, 0.125" (3.2mm) at the rabbet of the sternpost, and 0.18" (4.5mm) at the bow.   

Allan