Wooden Mast Repair

[MastSplit]

I have a 1949 cedar strip International 14 in really good shape. However, the original, hollow, laminated 26 1/2 foot Sitka spruce mast has a fine lamination separation about 6 feet from the base of the mast. I think it's repairable but I am in need of an expert's opinion as to how best to achieve it.

I think if I "load up" the mast by bending it slightly to open the lamination, I could inject a good adhesive (name one please) and then release the bend load, reverse load it to cause the lamination to close, clamp it and then fibreglass the area with 4 oz cloth and resin.

What do you think? What is the best glue/adhesive for this application? Any comments?

Mastsplit in Ottawa, Canada

[Meanz Beanz]

I'd be tempted to use something the vintage of the mast, epoxy would fix it but you may be creating other issues with the epoxy creating a stronger stiffer less flexible joint i.e. loading up other parts of the mast. Then again I don't know that is a real concern, quite possibly not & epoxy might be the way to go.

I think they where using glues like resorcinol back then but? Anyone you can ask that might know what the original glue was?

[MastSplit]

Thanks for the reply, Meanz Beanz (what a name!). I'll try to find a Canadian source for resorcinol but my attempts so far have been entirely in vain.

[Meanz Beanz]

Originally Posted by MastSplit

Thanks for the reply, Meanz Beanz (what a name!).

In the end it all means beans

I'm not really sure about resorcinol glue, its just the only older glue I can think of. There are probably folk here who know much more about that, from memory I think it was red, so if you have redish glue lines it might be the stuff.

Epoxy I would think is fine, but I get wary of unintended consequences these days Like doing that old radiator hose and then... U know the rest.

Cheers
MBz

[Landlubber]

yeah resorcinal is a two pack glue, there is a fine powder that is mixed with the dark red paste, to form the glue. It was used extensively till the late 70's when epoxy came into flavour.

It is the red glue line that was seen on waterproof plywoods for many years.

If the mast has enough fractures along the glue line, i would op[en it up, dress the wood and reglue the whole kit and kabangle.

[PAR]

I use resorcinol for painted masts and plastic resin for brightly finished sticks. These are the traditional adhesives and both work very well.

With age, these adhesives can get brittle. So, if there are sections where the glue line has parted company with the joint, then it's very likely the rest of the glue lines are not far behind. The best recommendation is to disassemble the mast and re-glue her up.

The inside of the mast will be coated in varnish or more likely shellac, which is more waterproof. Unless you intend full encapsulation of the staves, then avoid epoxy.

For what it's worth, epoxy will NOT provide any additional strength to the mast, unless you add reinforcement (fillers, fabrics, etc.). Epoxy alone is a coating with excellent moisture resistance. Epoxy with a reinforcement is an adhesive, which can be used to fill depressions, adhere sheathing, bond parts and structural elements, etc.

You can repair the mast with additional glue in the open seams, though I suspect, you'll see new ones by season's end.

Remove the paint or other finish coatings and examine the glue line. If it's purple, it's resorcinol, if it's brown it's plastic resin, if it's tan or lighter browns and yellows, it's probably a hide glue (Elmer's wood glue type). With the exception of epoxy, these glues need lots of clamping pressure to work well and most are temperature dependant, so read the instructions.

Is this a duplicate thread?

[Meanz Beanz]

When I said epoxy I was meaning an Epoxy adhesive, Epiglue or some resin powder mixture.... not just straight epoxy resin.

[Meanz Beanz]

Originally Posted by PAR

If it's purple, it's resorcinol, if it's brown it's plastic resin, if it's tan or lighter browns and yellows, it's probably a hide glue (Elmer's wood glue type). With the exception of epoxy, these glues need lots of clamping pressure to work well and most are temperature dependant, so read the instructions.

Is this a duplicate thread?

Good to know.... and yes.

Cheers
MBz

[Gilbert]

PAR, I am astonished to see your inference that epoxy is not an adhesive. Everything I've heard and read is that it is an excellent low pressure, gap filling glue and I've been using it as such for a long time and very successfully too, I might add. Should I try to get my money back?????

[PAR]

I don't believe I said that epoxy wasn't an adhesive. I did say that without reinforcement, just "painted" onto a surface it's a coating, not imparting any strength to the substrate which it's applied.

Epoxy has to have reinforcement or it's just a brittle plastic film that is quite good at resisting moisture ingress.

This said, sure you can use neat epoxy between two objects as a glue and it will stick, but without the reinforcement(s), it's of limited value.

Maybe I should have been clearer in the above post.

[bntii]

Par- have you gone the mile with the new Tite-bond series? Type III?

I have used the type II for tillers and like layups which see plenty of weather and had very good service. The type III may be getting to the place where a readily available one part will serve for lots of these applications.

http://www.titebond.com/WNTitebondIIITB.asp

I am not using epoxy on anything out in the weather if the section of the components is greater than about 1/2". The glue will not fail- epoxy is plenty strong- the joint will fail however as the wood fibers tear loose adjacent to the glue line.

[MastSplit]

For all who are interested, here's how my split mast saga ended.
I stripped the mast of all stays, spreaders and fittings. I sanded it down to bare wood. I loaded the mast to try to open up the damaged split area (about 15" long) approx. 6 feet above the base of the mast. I cleaned out the split area with a sharp, fine knife and squeezed in 2-part West System epoxy. I wanted to use Resourcinol but here in Canada, I couldn't find a source...it's an environmental hazard so no one in the States wants to sell it to Canada. Canadian import laws are too restrictive. Since I am more than 100 km from the border...I decided to use epoxy. I clamped the split area overnight and then sanded down the resultant repaired area. Very clean and professional looking. I filled indented areas with more epoxy, let it cure and applied a sheath of 6 oz fibreglass cloth around the mast encircling about 25 inches of it like a horseshoe (allowing the gap for the open sail track). I used the dry method of applying the cloth so I could trim it to fit properly as the mast shape changes at this point. I applied more West System epoxy over the cloth and let it cure. I sanded down the cured spot and applied a second coat of epoxy. I sanded it to smooth it out.
On examining the rest of the upper part of the mast, I discovered that the seam had started to split (dried out old adhesive) so I split the mast for about 10 feet and sanded it to bare wood. I cleaned out the mating surfaces and then lightly coated the seams with West System epoxy. I clamped and let it cure overnight. Then I sanded it smooth and applied a light coat of West System epoxy using the "wet method", to the seam area so that a 2-inch wide x 9-foot, 9 oz fibreglass cloth strip would stick on it from the first repair area all the way up the mast over the seam to the top of the jib halyard pulley. I worked the cloth until it was straight and then lightly dabbed more epoxy over the partially wetted cloth. I let it cure. Next I spent several hours sanding it smooth. I added another light coat of epoxy over the first coat to smooth-out the job. After letting it cure, I lightly sanded it with 80 grit and applied Epiphanes marine varnish to the whole mast. Keep in mind that most of the mast was not fibreglassed...only the damaged area and the spit seam. What a beautiful sight. The mast is smooth and the fibreglass is invisible. There are no run marks and the strength and wooden integrity are retained. I can hardly wait to get it out on the waves to try it. Now I can deal with the stiff breezes up here on the Ottawa River (2 km X 22 Km sailing area) without worrying about losing my 60 year old mast.
Thanks for all your excellent ideas, chaps.

MastSplit