Skipjack by michael mott - 1/8th scale - SMALL - 19 foot open launch

[michael mott]

Further gluing and shaping.

The forward section roughed out, waiting for the aft section glue to set up.

 

The rough shaping done to the whole hull with the exception of the area at the bow and stern which will be sorted once the new keel is made.

 

It slips on and off the spline nicely with enough friction to to hold if I tip the board upside down.

Tomorrow will be a sanding day.

Michael

 

 

[KeithAug]

Ah! a sanding day. What joy. Just love the way the dust spreads its way around the house coating everywhere with a lovely soft velvet. Best done while the wife is out shopping I find. 

[druxey]

Friday, Saturday, Sanday!

[michael mott]

3 hours ago, KeithAug said:

Just love the way the dust spreads its way around the house coating everywhere with a lovely soft velvet.

Keith this is not possible, because my shop in independent of the house systems. and if it is sunny today as it was yesterday it will end up being "A Sunny Sanday" thanks for that Druxey.

The Balsa dust is certainly like flour though!

 

Michael

[cog]

So your not sanding, but milling ... very confusing all this talk about this days, and dust

 

On the other hand I love the way you are making your build log another example on how one can build a model from scratch ...

[KeithAug]

4 hours ago, michael mott said:

this is not possible

Michael - What about the stuff in your hair and on your clothes and shoes. I suppose you are going to tell me that you have a decontamination station built into the door frame and that you strip and shower before accessing the house - please don't post photographs - imagination is sufficient.

[michael mott]

2 hours ago, KeithAug said:

I suppose you are going to tell me that you have a decontamination station

No but I do set up a negative charge to the table and the dust is immediately attracted to it and not me, so no problem I already clean as I leave the shop.

 

 

[KeithAug]

36 minutes ago, michael mott said:

I do set up a negative charge to the table

Shocking!

[paulsutcliffe]

Ah! a sanding day. What joy. Just love the way the dust spreads its way around the house coating everywhere with a lovely soft velvet. Best done while the wife is out shopping I find

 

And that's exactly why im relegated to the garage!!!!



[Keith Black]

1 hour ago, paulsutcliffe said:

And that's exactly why im relegated to the garage!!!!

I'm thinking it's more like self imposed exile. 

[cog]

Keith, it has nothing to do with exile. Ever seen an average European garage? Normally it is big enough to get your car in, that's about the whole meaning of garage. After you've gotten it in, you get out of the car and it's shelter either by going through the open roof, if not available you might try kicking out the windscreen. Exile sounds pretty much the better option compared to detention in a mansize hole ... (probably without heating!)

Edited April 1, 2019 by cog

[michael mott]

Well all this talk of garages I happen to really enjoy my single car garage converted to a workplace.

 

There was a fair bit O' sandin' today

 

Now I'm getting nervous.

 

Now the serious stuff needs to begin with fine tuning the form I am going to need to be very careful going forward from this point, no cavalier sanding now.

 

 

I am thinking that the new keel needs to be made before going any further.

 

And because Mark Taylor did this some time ago I thought that it was worth a look.

 

I am in the general ballpark the photo is a bit distorted, I can see that it is going to be alright though.

 

Michael

 

 

[Keith Black]

14 hours ago, cog said:

Keith, it has nothing to do with exile

Cog, I was ribbing Paul about his garage situation. Paul's had warping issues with one of his builds (cheerful) because of high humidity plus it's colder than a well diggers backside in the winter. I wish Paul could get inside to do his modeling but obviously his situation won't allow that. And yes I have, but only in pictures, I know what he's up against. 

 Michael, sorry to hijack your build log. Beautiful work, I'll shut up and let you get back to it...........Keith

Edited April 1, 2019 by Keith Black

[KeithAug]

17 hours ago, michael mott said:

There was a fair bit O' sandin' today

Nicely done Michael. 

[druxey]

Until recently my garage was European sized, Carl. There is one other possible way out: Houdini fashion. It helped that I have some Hungarian genes and am reasonably slim. But we've now moved and it is much easier!

 

That hull is looking very nice, Michael. It's going to be very elegant.

[michael mott]

Thanks for all the visits and likes.

Discovered a flaw today! When I changed the length in the elevation I did not change the length in the plan view. Don't ask me why because I have no idea why I didn't.

I cut the inside shape of the keel but left the outside so that I could use it as a gauge.

 

It was when I stuck the profile of the hull onto this and put it onto the form that I discovered the issues. yes a combination of them. The bulkhead stations were the same on both the elevation and the plan, and there was some spacing error at the stern at station 20 and the plan view of the edge of the deck was too long and needed to be shortened. it was very confusing.

 

Once the errors had been corrected and the edge of the profile changed it left a couple of things to fix the hull form. First I had to add 3/16 aft of station 20.

 

 

Then the other issue needed to be fixed with a load more sanding because now the bulkheads were wrong at the bow and stern. Onward and upwards.

 

The stern after some extra sanding

 

The red tape represents the 4 inch wide plate that is fixed to the top of the keel and is tapered at the bow and stern. indicated with the blue pen.

The next shot shows the re-sanded form with the profile resting on it.

I will be adding some deadwood at the bow and stern.

 

This looks better

 

Before I go any further I will set the stem and sternpost with the deadwoods. and fix the top plate after placing the ribs on the bulkheads.

 

Michael

 

 

 

 

 

Edited April 2, 2019 by michael mott
photo out of sequence

[cog]

Micheal,

I do appreciate the effort you put into solving your problem. It seems most every build has it's perks.

 

However, wouldn't it be easier to cut of X bulkheads at the front and Y at the rear and remake them, add the fill blocks, and sand them down to follow the hull line. I can't suppress the idea it will be very hard to get the curvatures of the hull on both sides equal the way you work on it now, or it will be very difficult to realise.

[druxey]

Not to be critical; but I can't understand, as you make the bulkheads in two halves to start with, why you would not have incorporated the keel assembly at that stage. Am I missing something? At any rate, your solution is interesting!

[michael mott]

Good morning Druxey, I don't think you are missing anything. It is me who missed an error in my drawing, as it has turned out I would have not got the keel correct at the bow and stern from the drawings. 

I probably could have done away with the #1 set of ribs because after shortening the hull to match the overall length as per the numbers from Roger it would have been wise to reset the stations but I did not.

I really can see how the use of half models was one of the main ways to get the form right. Working from 2 dimensions with a soft form without using all the conventions of waterlines, and buttock lines to check the shape in hindsight was a recipe for what occurred, it would have been the better way to approach this. I will definitely have a greater understanding of this process on the next hull.  I will follow the plans of a tried and true hull, instead of a few measurements of a pretty boat, that are mostly of the inside and a bunch of photographs. At this stage I am confident that it will all come together and will fairly represent the actual boat.

I can also see why folk build kits.

I can accept that I needed to learn all this the hard way.

 

Michael

[michael mott]

7 hours ago, cog said:

I can't suppress the idea it will be very hard to get the curvatures of the hull on both sides equal the way you work on it now, or it will be very difficult to realise.

Carl, that did cross my mind but I thought that it would have been more work, the error was annoying but small enough that I was able to fix it.

 

Michael

[cog]

You are a far braver man than I would be. It just shows how the men are seperated from the boys

 

Glad you could fix it easily

[druxey]

After all, half the fun is problem solving, isn't it?

[Bedford]

The hard earned lessons are the best ones, we don't forget them easily.

[Kurt Johnson]

Michael,

 

It is always a pleasure to watch a true craftsman at work. You never disappoint and offer so much to be learned.  Especially when things don’t go right the first time, but then you find a way to make them perfect. I love reading and to me it’s better than the best novel following your work. 

 

Kurt

[michael mott]

Thanks for the comments and visits.

I have a question regarding the ribs in the launch.  In the following pictures are some tests with Castello and Yellow Cedar. I am told that the frames or ribs in this launch are 1/2 inch by 1 1/2 inch wide.

The bulkheads are for getting the shape of the hull correct, ostensibly. I have been attempting to form the ribs to the shape that is left in the form after sanding and this is not working I have snapped three or four while working to bend the rib against nature which logically does not make sense. if the section of these ribs were square I can see this working but not with these. What does make sense is to make the ribs follow the curve of the hull and lay them flat. This does not then add all sorts of twisting stress to the rib this is obviously not a big issue in the full rounded area but at the bow and stern.

 

I am inclined to space the ribs logically at the bow and stern and let them lie flat next to the hull there will be a slight twist which is ok but not the Houdini twist I was attempting.

 

 

And of course critical council is welcomed.......Keith.

 

I await the collected knowledge of the membership.

 

Michael

[michael mott]

Hi Kurt I missed your post as I was composing at the same time. Thanks for you kind words.

 

Michael

[shipmodel]

Hi Michael - 

 

Good problem solving there.  My solution would have been a lot less elegant than yours.

 

As for the ribs - could you take square section wood and bend it to your curves, then trim to the sided dimensions that you want?

It would be time consuming and wasteful of wood, but no Houdini need apply.

 

Dan

[Mark Pearse]

Hi Michael

 

I'm not an expert so I asked one: Ian Smith is a retired shipwright (see http://www.openboat.com.au/index.html) & he said that the Houdini method was not used - the ribs will lie as they want to & you will have trouble in getting any twist in them. However he did note that the Herreshoff's were an exception, for their small production boats they had matched moulds for the ribs so that all of them were perpendicular to the keel.

Edited April 3, 2019 by Mark Pearse

[michael mott]

Hi Mark thank you yes I can see that they can lie perpendicular to the keel but follow the curve of the hull at the same time .

 

Michael

[michael mott]

Mark, my that link is great those guys are insane... amazing sailors but insane 1000 square feet on a six footer now that is pushing the envelope.

 

Thanks again.

 

Michael