Tar On Hulls

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philae44

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Can anyone tell me why some people use tar on the bottom of a wooden hull. I understand that its common practice for steel hulled canal boats but is it the same for wood?
My old girl, a pitch pine on oak hull, has had at some time, a liberal coating of tar both on the exterior and interior of her hull below the water line. I am confident that this is not original as the normal paints can be found underneath. The tar is now completely perished and is being removed simply by scraping with a paint shaving hook. My intention is ( providing I am not advised otherwise) to go back to the normal paint method of red lead.
I would be very interested to hear any thoughts on this practice and any advise if I am doing the wrong thing.

<hr width=100% size=1>weekend gypsy on tour
 
Tar was used on hulls in the early days because it is water-repellent amd marine boring creatures don't like it. A better underwater primer than Red Lead is the proper thing sold by the paint companies like International. It is a grey colour. Keep your Red Lead for priming the topsides.
Peter.

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It could well be coal tar. This was used on railway sleepers (and on wooden boats) because of its excellent preserving qualities. If it is coal tar, wear a mask when removing it because it is very nasty stuff. Never burn it off! Highly poisinous! Hence why it is nolonger used.

Any regular underwater primer will do the trick (my favorite is TEAMAC Metaclor) but make sure you scrub it in well on the first coat so that it sticks. Dont use a roller cos the paint will just sit on top of the dust and dirt etc.

When ships were coated in tar used as antifoul, they used to beach the boats once in a while and put a match to the tar to burn off all the weed etc.

Shant be trying that one on my girl!!

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Black Tar Varnish is still available from Blakes and others. Blo.....dy awfull to try and remove, catches fire if you try to burn it off, clogs up the sander if you go that way, but I still use it!!

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The water supply authority in Melbourne used to line their steel water mains [I'm talking about the fouur foot diameter ones] with Coal tar enamel [=black tar varnish] to prevent corrosion from the water.. They experimented with other potions, such as Coal Tar epoxy, but nothing matched the old-fashioned enamel for effectivness.
Peter.


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When I bought my first boat, a 1937 Johnson & Jago, in 1970, the boatyard recomended using Synthaprufe on the bottom.
This was a chlorinated rubber bitumen used for damp proofing buldings. It was often used on elderly boats [we didn't call them classics then] to overcome minor leaks and as a preservative. It also proved an effective anti- foul as I couldn't afford the pukka stuff.
The problem came after two years as it built up really thick and was a 'orrible job
to remove.

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Sorry to say it, but Im sooo glad someone else is having problems with tar. Just about got it all off, appart from the bottom bits. Only advice I can offer is do it cold, night is best. I tried doing it on a nice hot day. The tar got all soft again, didnt come off just moved it around! So at night with a torch when the tar was at its coldest seemed to work a treat. Just chipped away :)

<hr width=100% size=1>Bertie :)
 
I have managed to get just about all of mine off now. Just a small patch left underneath so should have it done in a couple of days. However I don't think that mine is quite as bad as yours because just about all of it has completely perished. It does not matter what time of day, even in the heat of the last few days it still scrapes off quite well. I have encountered only one sticky spot on the entire hull. However such ease of removal still comes with a price, namely the state your in when you have had a few hours at it. One of the filthiest things I have come across, and yes it does get everywhere.

<hr width=100% size=1>weekend gypsy on tour
 
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