Pine pitch caulking.

[Clockmaker]

We are restoring a 1925 Dutch double ender and to make it as authentic as possible we would like to caulk the deck seams using the original Pine pitch . We have collected several gallons of White Pine pitch but it is very brittle in it's raw state. I have read that the caulking was a mixture of Pine pitch and other ingredients. Would anyone out there know the formula? Thanks, JL

Rockport Maine

[ssor]

It sounds like what you have is more of a rosin than a pitch. Rosin used to be sold as part of a family of products called "naval stores". Beyond that I have no idea how you could make it flexible and non sticky.

[Vinny&Shawn]

Go to WoodenBoat magazine classified, there are sellers of proper black pitch which it heated prior to use.Also the magazine has had numerous articles on how to mix, use and pay the seams with pitch. Many boat building manuals also over the topic.

[Todd Bradshaw]

One formula used on birchbark canoes was heated spruce gum or pine resin tempered with animal fat and some finely ground charcoal. Samples were placed on a piece of bark, allowed to cool and then flexed. If the pitch cracked, too much tempering had been added and more gum was added to the mix. If the finished product got tacky when held against your hand and allowed to warm, more tempering was needed. Your mileage may indeed vary.

[Thad Van Gilder]

Are you sure it wasn't just jefferies marine glue in the seams?

-Thad

[Thorne]

Do you intend to partially fill the seams with cotton or other fiber before laying the tar on top?

Won't you have issues with the tar/pitch/caulking being tracked all over the decks, cabins, and smeared onto clothing during hot weather? I've talked to operators of traditional vessels like the Nina replica and they've sometimes had to go for less trad methods to keep visitors un-sticky and happy, and below decks dry...

[Falcon500]

assuming its raw sap from the tree its most likely just the sugars that have crystalized, pine tar and turpentine are mostly extracted from "hard pines" like yellow pine but you may actually have rosin which is a super hard glass like substance that is most likely beer bottle brown or darker threre is an article in wooden boat on pine based boat building products ill try and find it and edit my post

:edit: yep Wooden Boat Magazine issue #203 page 44 has a recipe for pine based screw hole filler but i assume it can be used in conjunction with caulking to fill (pay) the seams

[Thad]

I recently poured a pitch and wax mixture into the bilge of a Crocker Sallee Rover. Crocker drew two construction plans for that boat, yawl and sloop, and in one he calls for pitch to the limbers and in the other, wax. I got What George Kirby called "semi-elastic pitch" from Kirby, commercially called Burgundy Pitch, which according to other sources mostly comes from Finland. George suggested that it be mixed with beeswax so it wouldn't be quite so brittle. Resin, as used in the WB #203 recipe mixed with beeswax, is a refined and powdered tree pitch very similar to Burgundy pitch. I melted them together and poured them into the bilge. Not so long ago there were devises like heated pitchers (interesting word that in this context) with very narrow snouts for filling deck seams.

[theskip]

Traditional recipe is just pitch poured over oakum. Period. Here is a link to a book that was published in 1918 and would've been accessible reference materials for the period.
http://books.google.com/books?output=text&id=Zu4OAAAAYAAJ&dq=%22pine+tar%22+paying+deck+-baseball&pg=PA37&lpg=PA37&q=pitch
This is as salty as I can imagine. To soften the pitch heat and add turpintine to suit.