Monday, 28 July 2014

caulking update

After studying various caulking videos on youtube and some good advice from an old shipswright we have started the caulking, we sourced the irons and mallets on ebay, we already had the oakum.

The key is having the right tools, using the feeding iron you push the oakum into the seam create a loop a little further on depending on size of seam and repeat three or four times, go back to where you started and knock the rest through with the iron.

After five or so minutes you start to feel the depth and read the sounds from the mallet and iron,

Very satisfying...

Masking tape over caulked seams

Saturday, 19 July 2014

Red sky at night shepherds delight

Red sky in the morning shepherd's warning

Tuesday, 15 July 2014

Black pudding sample, caulking tools and practise board

The mallets have arrived, two solid pieces of craftmanship in themselves, we have now have a set, the weather is with us so we have been reefing out the old oakum and working on the Oak planks, there have been a few patches that we have had to fill with Smith and Co's epoxy   Fll it filler, available from the link, an epoxy filler made with wood fibres, ideal for wooden boats which has saved us alot of time and money, we have salvaged planks that previously would have had to have been cut and joined.

The tools and oakum

We also made a tool using two bits of kindling wood an old rough saw blade held together with gaffa tape which was very useful for reefing out the old oakum.

We knocked up a sample of our own version of the black pudding filling compound mix, we have also ordered five litres of the current marketed black pudding, isoflex rubber paint and portland cement and also another mix we have read for under the water line anti fouling paint and portland cement.

The black pudding, we were dubious at the time however we did try to use it straight after mixing, we were surprised with the findings the next day.

We put it in and using linseed oil we smoothed it of, in the morning it had cured and expanded, we tried to pull it out, with enough force you could split it but it was in firm, we broke piece of and noticed that the portland cement had created tiny air bubbles so the mixture had expanded.

We have also been practising caulking with a piece of tongue and groove.

Another idea for the finished paint job

Sunday, 13 July 2014

A new week

The weather is finally with us the Tino has been under cover, eight tarpaulins to be precise.

We want to use as many original tools as possible, we now have two original mahogany mallets and a selection of irons, before we start we are going to do a sample of our black pudding mix.



Tools so far

Saturday, 12 July 2014

Black Pudding filling compound mix

I have read the term black pudding, a tar and portland cement mix used to make a strong filling compound for larger working boats, the caulking we have just removed is definitely tar based and had badly blown and cracked, after replacing the decks with Isoflex a liquid rubber mainly used for flat roofs which replaces tar we are going to do a test with Isoflex and portland cement make a paste and test its drying time and strength.

Isoflex data sheet.

We will post our findings.

The result after one night, a success

For any caulking enquiries please call A and D Wooden Boat Marine Services 07765 195 118.


We are going to be using oakum for the bottom and upper planks, after further investigation the cotton is more suited to yachts, when reefing the original caulk it was quite obviously oakum, luckily enough there are two large bags in the engine room, we have managed to find an original mallet and two additional caulking irons, we are going to need an iron and a hardener.

Our seams

Tools so far

You can also modify a small and large bolster to make replica irons and use a dead blow mallet, we will be using both.



From Wikipedia, the free encyclopedia

Oakum and tools for caulking.


Prisoners picking oakum atColdbath Fields Prison in London.
Oakum is a preparation of tarred fibre used in shipbuilding for caulking or packing the joints of timbers in wooden vessels and the deck planking of iron and steel ships, as well as cast iron pipe plumbing applications. Oakum was at one time recycled from old tarry ropes and cordage, which were painstakingly unravelled and taken apart into fibre. This task of picking and preparation was a common penal occupation in prisons and workhouses.
In modern times, the fibrous material used in oakum is derived from virgin hemp or jute. The fibers are impregnated with tar or a tar-like substance, traditionally pine tar (also called 'Stockholm tar'), an amber-coloured pitch made from pine sap. Petroleum by-products can be utilized for a tar-like substance that can also be used for modern oakum. White oakum is made from untarred material.


The word oakum is derived from Middle English okome, from Old English ācumba, from ā- (separative and perfective prefix) + -cumba (akin to Old English camb comb)—literally "off-combings".
Picking oakum was a common occupation in Victorian times in British prisons and workhouses. In 1862, girls under 16 atTothill Fields Bridewell had to pick 1 pound a day, and boys under 16 had to pick 1.5 pounds.[1] Over the age of 16, girls and boys had to pick 1.5 pounds and 2 pounds per day respectively.[1] The oakum was sold for £4 10s (£375 in modern money) per hundredweight (100-112 lb).[1] At Coldbath Fields Prison, the men's counterpart to Tothill Fields, prisoners had to pick 2 pounds per day unless sentenced to hard labour, in which case they had to pick between 3 and 6 pounds of oakum per day.[2]
In Herman Melville's novella Benito Cereno, crew members of a slave ship spend their idle hours picking oakum.
Charles Dickens's novel Oliver Twist mentions the extraction of oakum by orphaned children in the workhouse. The oakum extracted was to be used by navy ships, and the instructor said that they were serving the country.
The Innocents Abroad, a novel by Mark Twain, also mentions in chapter 37 a "Baker's Boy/Famine Breeder" who eats soap and oakum, but prefers oakum, which makes his breath foul and teeth stuck up with tar.
While discussing the appropriate attire for American Supreme Court justices, Thomas Jefferson was once famously quoted as saying, in reference to traditional court dress: "For heaven's sake, discard the monstrous wig which makes the English judges look like rats peeping through bunches of oakum."[3]


Oakum can be used to seal cast iron pipe drains. After setting the pipes together, oakum is packed into the joints, then molten lead is poured into the joint, creating a permanent seal. The oakum swells and seals the joint, the "tar" in the oakum prevents rot and the lead keeps the joint physically tight. Currently other methods, such as rubber seals, are more commonly used.[4]

All caulking work will be by A and D Marine services 07765 195 118, please call for any enquiries.

Friday, 11 July 2014

Learning to Caulk, wide seams irons mallet explained

The time has come to start caulking the hull, we have raked out the old oakum and caulk, we have everything we need to get started.

I have for some time been researching the original technique the tools for a boat of Tino's size and stature, there are various techniques depending on the wood the type of vessel the width of the seams, cotton or oakum, the worrying thing with Tino is the width of the seams, she has sat out in the weather for some time and the planks have expanded and shrunk during the hot and cold weather creating large seams.

What we do know is that the original techniques and tools will be employed, we originally posted a picture of cotton more commonly used for yachts and smaller craft, we will be using oakum.

We also posted an article regarding the procedure for caulking really old planks which we will be employing however we will not be using the filler compound suggested we are using an old recipe for black pudding, explained in another post.

Steve Smith from Smith and Co CPES recommends 3m 5200 however our previous post warned that this was too strong, there are alot of options we are going for black pudding.

I found this website with the most informative video regarding the above.


Caulking is defined by driving oakum, cotton or general rope fibres in the seams of a ship's wooden deck or side / hull to make it watertight. It also plays a structural role in tightening up the hull / deck of a ship and reduces the longitudinal movement of neighbouring planks.
It is very easy to demonstrate the principles behind caulking a vessel, however, it is a skill where practice is  important but also individual vessels present their own issues. Usually you will have to warm to the task, understand which iron you  have to use, and how much oakum. There is a lot in the skill that simply comes from experience and new builds present different  issues to old boats.
The final pitching of the seam was not demonstrated because it was not occurring at the time of the  demonstration.


The process is demonstrated in the accompanying video clips with a step-by-step guide. The conversation with the boat builder, in this case, Chris Rees is unscripted and covers the technique from his experience.
The technique is very simple but the subtleties come with experience:
  1. Clean the seam to be caulked.
  2. Twist a length of caulking material (oakum or cotton). The length of material to prepare will increase with experience and  speed.
  3. Lay the material into the seam using the making iron and caulking mallet (some people use a normal wooden mallet but never  a hammer). It is tapping not hitting the irons. Wide seams may need ‘choking’ with a double gather of caulking material.  If seams are too tight they may have to be worked with the dumb iron first, this will open up the seam so caulking can occur.
  4. Seam is gone over with the hardening iron to firm up the caulking material in the seam and caulking is complete.
  5. Seam usually paid with pitch or tar (not demonstrated).
If a seam is stopped midway, leave the oakum attached if possible. If  you have to break off the oakum or run out and need to start a new bail / ball, twist the ends together so they become one.