Wednesday, 16 August 2017

Cutting in the Waterline.

My build-plans make no reference to the waterline, the only mention is the draught (draft) which is 8 inches or 200 mm. Yet I need to know exactly where the waterline is, as the underwater section is red, and blue above. I can't guess where it lies because the odds are that I'd get it wrong and end up with the paint-finish looking 'skew-wiff'!!

On Youtube I watched them carry a boat out and put it in the water, then go around with a marker and mark in the waterline. No way I can do that.

I then watched how the professionals did it and larger vessels. They used very expensive laser equipment, which I can't afford...
                                                          .... or can I?
I got one from Screwfix it was made by Bosch and cost £50 ($65).

From the centre of the bottom of the transom I measured down 8 inches and marked a point. Next a spirit level was used to draw a horizontal line across the transom: the only flat surface on the boat, the rest is complex curves.

Horizontal Pencil Line on Transom

The laser leveller was now set up.


The machine self-levels and in normal conditions - setting it up 5 - 10 yards (metres) away - would project the horizontal line the whole length of the boat. As it is, I only have one yard each side which, as you can see above, gives me a short line.

The machine was moved along until the end of the laser touched the pencil mark on the transom. Marks were made with a 'felt-tip' marker at short intervals along the horizontal laser line. The machine was moved further along numerous times until I reached the stem.
The marks left with the felt-tip marker just visible 

I then repeated the process on the other side, starting at the transom. My check would come if I ended up at the stem exactly in line with the previous line. They met within a 'gnat's whisker'.

Starting aft, I place a continuous strip of masking-tape along all the felt-tip marks.


   
I'd got myself a waterline! It is not where I would have guessed it would end up

Friday, 11 August 2017

Primer

Today I put on one coat of Epifanes Multi Marine Primer which took exactly 750 ml (1.3 pints).



This is reputed to be a good filler as well as a grounding for further coats of paint. I shall give it a good sanding down and re-coat in a few days.



Thursday, 1 June 2017

Fixing Them Holes

A few posts ago you can see how the fibreglass blanket I epoxied over the hull had developed quite a few bubbles in it. The temptation is to ignore the bubbles and paint over them. The problem then is that those bubbles are brittle and will shatter if banged, and this will then lead to a major problem of repairing not only the hole in the fibreglass but the ruined paintwork.

Working in small areas, I have been bursting the bubbles and removing the chards, which leaves a hole through to the wooden planking:



I then filled the holes with a mix of epoxy resin and filler powder.


I will sand these filled holes down tomorrow.
You will have noticed how the lovely polished varnish effect has gone for I have sanded the hull all over.


This process of coating and then sanding will go on for weeks until we reach the final finish!

Sunday, 28 May 2017

THE SECRET WEAPON That Put The Icing (Frosting) On The Cake

It was on the American website that I follow religiously, http://www.offcenterharbor.com, that I discovered the secret-weapon!

When one uses epoxy as a glue or as a filler, one has to deliver it to the area in which it is to used as efficiently as possible. I've tried trying to get it in place with a palette knife, pieces of wood and with a scraper. Although these ways work, it is very inefficient and......sticky.... and I have a bad reputation with sticky things!

Enter the secret weapon: the humble icing (frosting) bag, often called a pastry bag.

Icing/Pastry Bag
For the uninformed, this is a conical bag into which bulk icing  is placed. The tip of the bag is then snipped off to the required size. The bag is then squeezed and the icing emerges, very much like toothpaste out of a tube, and piped around the cake.

The problem I found was that when I put the glue in the bag, half of it got wasted sticking to the length of the inside of the bag: I only needed the bottom quarter of the bag, as epoxy goes-off very quickly so you can only work in small quantities.

My own invention was to put the bag in a tin (can) thus:


I mixed my epoxy glue in a yogurt carton and then scooped it into the bag:


Next I piped the glue beneath the bilge runner, which was loosely held in place by screws:


Finally, I screwed the runner into place, not too tightly but just enough for the epoxy to squeeze out a little (the epoxy's adhesive quality  secures the joint and not the pressure from tight screws, unlike many glues).

I then ran my gloved finger along the edges forming the squeezed out glue into a fillet.



Saturday, 27 May 2017

Outer Stem Completed

Trying to laminate the five pieces of hardwood that go to make up the outer stem was complicated and took a long time. As I mentioned earlier, trying to steam-bend the pieces during the winter let to them splitting.

I finally finished the stem yesterday. Each piece had to be glued in situ, and then held in place by panel pins and, where the bend was tightest, screwed. When the glue had set I removed the pins & screws before repeating the process for the next piece.

Where the stem met the planking an irregular bead of white glue was painfully obvious to the eye. Similarly, the joints between the laminates could clearly be seen. 


The white line between the stem and the planks is an irregular bead of glue

Using a sharp chisel I got rid of most of the volume of glue. Next the sides of the stem were  planed and sandpapered. Finally, I covered the sides of the stem with epoxy resin mixed with filler powder to a peanut butter thickness. I covered the sides of the stem with this, neatly filleting it onto the planks.



I've fitted the runners along the bottom, with screws, although they still have to be glued in place.





Friday, 19 May 2017

Which Paint?

Sometimes I have to remind myself that one day this boat will get finished and look something like this:


In the meantime, I need to prepare the hull for painting.

Preparing the surface will involve filling and patching (see previous post) followed by degreasing.

Degreasing



The outer shell of the glassfibre/ epoxy has a layer of gelcoat. This will need to cleansed using a degreasing fluid.

Sanding (or Abrading).

Every video I see involves the use of a 'random orbital sander'. I take particular notice of :




This is a really wonderful (US) site and worth subscribing to: full of advice and practical videos on small boats. So I bought a sander & sanding disks on their say-so.  
Quantity of Paint Required (Areas to be Painted)

It's no good guessing at the quantity of paint, firstly, one needs to know the areas to be covered - I used this formula from the suppliers of my boat plans

SELWAY  FISHER DESIGN

There are two areas I'm interested in are,
 (a) below the waterline (the Load Water Line, LWL) which is the green area in the top photo.

        ....and...

  (b) above the waterline: from the top of the green area to the gunwale. Here the Length used with be the Length Over All  (LOA) ... not forgetting there are two sides! Where 'B' is the Beam (width at fattest part!) 

     Above             (LOA x B) x 2 x (Average Freeboard)
                                              (4.57 x 1.8) x 2 x (0.48)  = 7.8969 rounded to 8 sq mt

    Below               (LWL) x (B x D)
                                             4 x 1.8 x 0.5  =  3.6 rounded to 4 sq mt


....... and then the problems started ....

I got so much information on different types of paints I didn't know where to turn next ..... this video got me pointed in the right direction

http://www.offcenterharbor.com/videos/painting-a-wooden-boat-simple-techniques-professional-finish/

The next problem was locating the paint. typically, if they had the paint they didn't have the colour (color), or in the right quantity. Then, by pure chance whilst browsing deck fittings on the site from whom I bought most of the materials for Seagull, I found they do the paint... further, if they didn't have it they would get it in 4 days.

Using the areas I calculated and using the area a pot of paint covered in square metres (sorry US friends, I prefer square footage too) I was able to come up with this list, plus all the extras:
Size
Quantity
Description
Colour
750 mm
2
Epifanes Multi Marine Primer
Grey
750 mm
4
Epifanes Mono urethane
Dark Blue equivalent to 214 on Enamel Paint Chart
1 litre
1
Epifanes Paint & Varnish Thinner

750mm
1
Epifanes Interimcoat

Small
1
Epifanes D-601 Thinner

750mm
1
Epifanes Foul-Away.
Red






Here's the quote in British Pounds (US multiply by 1.3)

UPDATE ON BUILD
To finish steam-bending the outer stem I adapted my drain pipe - which bent under the steam, by taping it to some stout timber ....it worked out (below)




Thursday, 6 April 2017

WINTER'S OVER!

It's about four months since I last posted. I confess that the disappointment with my application of the Epoxy Resin did take the wind from out of my sails, but there was more reasons to it than that for the long gap.

The cold weather (can't work if the wind's from the north) kept me 'grounded', and then it was Christmas and so on and so forth. This, however, is not a journal about my private life, but the log of the building of Seagull. To anyone reading this blog in years to come there will be no obvious gap in the build. So what have I been up to today?

I began by fixing the problem near the bow where the Epoxy resin had bubbled up. I broke the brittle bubbles and gave the whole area a good sanding. This is what it looked like:

Before

I then cut out a piece of the fibre glass cloth to patch over where the bubbles had been - I had read this was how to repair the hull if damaged.

After one coat of Epoxy Resin, the area now looks like this:

After patching (the white marking is ok it's only sanding marks)

I also mixed epoxy resin with filler modules and filled the holes on the transom:
Before

After

This left the broken piece of wood on the stem - which had snapped in the freezing weather:



I removed the broken piece and glued it back together again. Next the steamer: kettle and drain pipe were returned to action. The wood went into the pipe and steam from the boiling kettle passed through it for 30 minutes.



The previously snapped piece was quickly screwed and glued in place - successfully.