Wood Choices, types and locations....

[Jim Cate]

I've seen multiple failures

Ahhh, they should have "hired a pro", right?

Jim

[Terra Nova]

Originally Posted by Jim Cate

Ahhh, they should have "hired a pro", right?

Jim

If they're not sharp enough to do their own due diligence or figure it out for themselves, yeah. It doesn't pay to use cheap, inferior glue. What will you save, a few pennies per glue joint?

[Jim Cate]

Originally Posted by Terra Nova

If they're not sharp enough to do their own due diligence or figure it out for themselves, yeah. It doesn't pay to use cheap, inferior glue. What will you save, a few pennies per glue joint?

Actually, the ogre of cost hasn't been raised in this thread by anyone but you,, TN. This poor chap is looking for a good set of parameters: timber and adhesives. He hasn't whined about cost at all, rather the contrary,but has been getting conflicting advice on all fronts: timber and glues. You, as always, have strong opinions,stated firmly but without much beyond your experience to support them. You say that plastic resin based glues have frequent failures, others seem to have had good results, including Cecil Lang (sp?) whose credentials are pretty good

One of the good things about CF is the wide variety of backgrounds and skill sets represented by posters. One of the bad things about CF is... that same wide variety,which leads to the above noted conflicting advice offered to folks with problems and questions.

I personally like epoxy for this sort of project, mostly because I know that my carpentry skills are pretty ordinary (on a good day). But it is undeniable that resourcinol (sp? is strong and reliable, and that some folks have good results with the plastic resin glues. Blanket condemnation without good citations to support it is not helpful to the confused OP... ever!

So, for the OP... I wish I had the knowledge to set you straight, but not the case, so read carefully, look up some references and realize that all the schemes that have been suggested (I think) have successful histories in some hands. I think your chances of producing a good mast are pretty good, so hang in there!

Jim

[Wotname]

Originally Posted by roland stockham

I suggest that the quality is more important than the species. Any of the straight grain lightweight firs will make a mast, some being a bit more durable or harder wearing. But the big difference is the quality.....

+1. This is true!!!!

Originally Posted by CarinaPDX

.......... Resorcinol glues are shipped in two parts, and combined to make the glue. If the fit is perfect, the glue is not old (2-3 years shelf life), and the temperature and humidity are within specified range it is probably the best possible choice. Just don't use it if these conditions aren't met.
..............

IME, Resorcinol glues require perfect carpentry and attention to detail regarding temperature and humidity. It is great glue when done properly.

Epoxy is a great choice for those (like me) can only do good to very good carpentry and have to deal with the climate of the day.

[Michaeltouche]

Originally Posted by Pauls

The best glue for your mast is resourcinol. It is the best wood glue available, period. Epoxy is very popular, principally because you can do a lousy job of joint fitting and fill it with epoxy. Joint fitting is very simple on spar bulding. Do your homework on this, you'll find what I'm saying is accurate. I've seen many failed epoxy joints on spars.


If you're bright finishing the spar and don't like the purple resourcinol glue line I'd suggest Plastic Resin. It is an excellent wood glue.


So, find some high quality doug fir. Do a good job of jointing. Use a first rate glue. And seal all penetrations of the wood for fastenings really well.

there doesn't seem to be a consensus with the type of glue to use....

[tankersteve]

Originally Posted by Jim Cate

Actually, the ogre of cost hasn't been raised in this thread by anyone but you,, TN. This poor chap is looking for a good set of parameters: timber and adhesives. He hasn't whined about cost at all, rather the contrary,but has been getting conflicting advice on all fronts: timber and glues. You, as always, have strong opinions,stated firmly but without much beyond your experience to support them. You say that plastic resin based glues have frequent failures, others seem to have had good results, including Cecil Lang (sp?) whose credentials are pretty good

One of the good things about CF is the wide variety of backgrounds and skill sets represented by posters. One of the bad things about CF is... that same wide variety,which leads to the above noted conflicting advice offered to folks with problems and questions.

I personally like epoxy for this sort of project, mostly because I know that my carpentry skills are pretty ordinary (on a good day). But it is undeniable that resourcinol (sp? is strong and reliable, and that some folks have good results with the plastic resin glues. Blanket condemnation without good citations to support it is not helpful to the confused OP... ever!

So, for the OP... I wish I had the knowledge to set you straight, but not the case, so read carefully, look up some references and realize that all the schemes that have been suggested (I think) have successful histories in some hands. I think your chances of producing a good mast are pretty good, so hang in there!

Jim

This post is quite succinct in the general problem with Terra Nova's posts. They are very abrupt, and often unsupported with evidence. This is repeated across numerous threads.

TN claims 40 years of boatbuilding experience. That is great. However, it is just a claim, as this site doesn't vet anyone or their experience. Linking a claim with some facts (as several posters did) usually is interpreted as more credible and helpful. And while 40 years is a remarkable body of work, we also don't know the frequency of repair, preponderance of work, or anything else.

Terra Nova, your 40 years of boatbuilding didn't teach good forum etiquette. You come across as terse to the point of rude. You may be right in every post, but we would never know, as you don't provide anything but your experience as to why you are right. I know that I would value your posts much more if you expanded on your viewpoint or offered a reference, backing up your point.

I don't think the OP owes TN an apology. The OP may be new, but he was looking for informed ideas, not simply what sounded like opinions in TN's first post on this thread.

Tankersteve

[jimbunyard]

Wellll...in typical CFF (Cruisers Forum Fashion), let's dissect and detail...

For starters, to pull out the 'experience' card, been building wooden stuff since I was five, so that makes 54 years...but responsibility is of course your own account.

Since it appears you've decided on douglas fir, there seems to be only the question of glue...

That is easily and pragmatically decided. If you're accustomed to making furniture or instrument quality joints, resorcinol might be your best choice.

If your joints are of slightly lesser quality, epoxy is a good choice, probably the best one. Match your hardener to the size of the job and ambient temperature of the environment you're working in.

There is another question though, and that is what type construction you're using. If simple box construction, then ideally you should two different 'cuts' of lumber, especially if you're screwing as well as gluing. As shown in the first picture below, a flatsawn plank should be screwed to a quartersawn plank.

If you're using birdsmouth construction, as in the second picture, then all the planks should be quartersawn, or as close to quartersawn as possible, though this may be rather difficult to do in practice, as, unless custom sawn, lumber nowadays is sawn with economics more than utility in mind.

That being said, the third picture is of an offcut of a double-walled, birds-mouth pedestal I made a while back, showing construction with basically all flatsawn lumber...glued with Titebond Three wood glue (alphiatic resin, I think).

[Terra Nova]

Originally Posted by tankersteve

...TN claims 40 years of boatbuilding experience...Linking a claim with some facts (as several posters did) usually is interpreted as more credible and helpful...Terra Nova, your 40 years of boatbuilding didn't teach good forum etiquette...

Tough.

Do your own due diligence. And don't expect others to do your research for you.

[Cheechako]

There certainly is a lot of Brue ha ha in this thread about who is right and what wood is best. The choice of wood is a compromise as is most everything on a boat. Spruce was used quite often because it is significantly lighter weight. Weight matters on a spar. An extra 20 lbs 25 feet up is going to require 500lbs more ballast to equal the righting moment. Thus Spruce is often used. It all rots without extreme care in protecting it. Doug Fir rots real fast without protection, we have it laying everywhere up here in the PNW. Western Red cedar is great but as we all know it spits readily. There are farmer's fence posts made of rough split Red Cedar sitting in the ground here since I was a kid, so 50-60 years unprotected in the wet damp Washington ground. I'm sure they are rotten at the bottom but still standing.
FOr use today finding old growth FIr is going to be hard. Trust me, what they call Fir now days isnt anything like it. Most often it's a hybrid sometimes called Hem-fir. It is softer, lighter and very rot prone.

[Pauls]

Lots of inaccurate info from Terra Nova here.

If you want a source for truly definitive wood properties go to Forest Products Laboratory. They are a US gov't funded research lab for all things wood. Solid science and engineering data, the standard industry data source for a very long time.

Regards glues, again Terra Nova's statement contradicts experience of many experienced boatbuilders. I learned about Plastic Resin from an old mentor who had used it exclusively to build hundreds of 26 to about 40' plywood powerboats. I built my first boat, a 38', exclusively using plastic resin. She's over 40 years old now and, last I heard, still going strong. I agree with Jim's summation on glue choice. I'd just add that if you're making a typical box spar then jointing is very simple and in that situation resourcinal is the best glue available.

All the room temperature cured epoxies have very low glass transition temperatures, typically in a range from 105 to 130 degrees F. Anytime you heat an epoxy above its glass transition temp and apply any stress to it is permanently weakened. It is almost impossible for the glue to not see stress in a heated environment due to thermal expansion issues. Epoxy in a hot, ie tropical environment is almost certainly going to weaken over time.

I specify adhesives for specific applications as part of my job. The adhesively bonded part is then put thru thermal cycles replicating its designed for environment and then tested to destruction to verify bond strength. This is real world science. I can tell you that when the glass transition temperature is less than the peak temperature the bonded parts see that the bond strength is significantly degraded. Real professional epoxies always list glass transition temperatures. Boat building stuff almost never does.

[Pauls]

To add to my last post, here is a really good wood glue. It is a gap filling resourcinol. Does not require perfect joints and does produce bonds stronger than the wood with the long term durability resourcinol is famous for. https://www.chemical-supermarket.com...&cat=14&page=1

I should have posted this earlier. This website is a great resource for specialty adhesives, lubricants, coatings, etc.

[zeehag]

my favorite cf bs is those who require argumentativeness and disrespect against someone who has actually experienced the issues and repaired the issues against which they argue. totally rude and uncalled for.
michael, i may have a 48 ft spare and a 40 ft repair mast... but i am in mexico.
we have located a rot free "thai cedar" set of freshly varnished masts leaving mine possibly available. i will keep you posted. wont know absolutely until november. that is tomorrow in mexican. hahahaha
we will be repairing or replacing sprit as this project continues. i can see all my horizontal spars being perota, aka huanacaxtle wood. is resistant to rot and
insects and is gorgeous, sharing the antiskid traits of teak. as our boats share the hollow box constructed masts, these are not a s heavy as folks would imagine. my mizzenboom is made of this beautiful wood, as are my nav lightboards and some other items.
your choice o f doug fir is a good one.. the doug fir double plank laminate mast i was fortunate to find available here is gorgeous once paint is removed. that mast is over 30 yrs old and nearly perfect. there is base rot, as i have continually found in spruce and fir masts, but not as much as the spruce ones i examined in my searches for solutions to this mast rot issue. my findings are those which i posted earlier and was smacked down for having written. oh dear. i was writing facts and findings, not opinions. big difference.
seems my mast material is the ideal wood for mast building. mine was declared to be thai cedar by an alleged wood guru. in person.
i think he smelled and tasted pad thai in the grains under the paint when he scratched sniffed and tasted it.. hahahahaha. whatever it is, only perota rivals it for rot and insect resistance.

[Copacabana]

Zeehag, perota, or peroba, is very good wood, but quite heavy. Have you found a big difference in the weight of your spars? Also, peroba has a tendency to start splitting and cracking when exposed to the elements. It's a good idea to keep an eye on the spars and their varnish (or whatever coating you used).

I suspect "Thai cedar" is not from the cedar family. For some reason "cedar" (or in Brazil, "cedro") has been adopted to describe some tropical woods. Do you know the scientific name of Thai cedar?

[Brnstrmr]

Hi MichaelTouche! I am about to begin multiple facets of work on my Mermaid C/C and am curious how you are coming along with yours? Cheers!

[Michaeltouche]

If I could re-start up this thread with another question.... What about a solid mast.... I am going up tomorrow to start a new home build in the Mountains and we're cutting down some..... Douglas Fir.... YA!!! Was wondering if I can make the mizzen solid...pros/cons there are at least a half dozen masts on site... either way, i'll use this lumber