"tube type" glue for blocks?

[sr. jigaboni]

I recently was gifted with a case of PL adhesive, the small tubes, and they say 100% waterproof. I have some nice white oak for making some made blocks, and was wondering about this stuff.

Does anyone have any experience using this stuff in an application like this? I plan to make some blocks that will be glued and riveted, and I wondered if this stuff would work. I've never used these types of glue for anything except my kitchen, but they do be sticky there. Are these glues affected by soaking in oil? (to make the blocks weather resitant) These are all on drysailed boats... all six of them.

I would like to replace all the blocks in my arsenal with wooden ones, mostly to keep from doing other stuff. Oh yeah, i got enough offcuts of UHMW plastic to make about a gazillion sheaves, too. I'd probably feel more comfortable not using epoxy in this case, so input is appreciated.

also,as a follow up to my glue-lam post, I also found a 30 foot 40+ year old DF 6x12 (actual), that was a load bearing beam in some building that has bolt holes almost exactly the size and spacing I need fpo ballast bolts. If I build this boat, i'll only have to drill for floor timber bolts. 1 piece down, 986,843 more to go. smile.gif

[raymacke]

You might want to look at these links - PL-1 (http://www.simplicityboats.com/pl_premium.htm)
and PL-2 (http://www.simplicityboats.com/jointtest.html) . Also this post has some info. It is long but there is info scattered within POST (http://www.woodenboat-ubb.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=011233)

[Bob Smalser]

So long as you include those rivets, poly sealant/construction adhesive should work fine.

But I still don't understand why so many folks tout poly sealants as a suitable marine "glue".

I had to build a work punt in a three-day-hurry for a short notice logging job several years back and instead of a proper caulking job between the PO Cedar fore-and-aft bottom planks, I used 3M 5200. The planking was at 19% M/C at the time. Then I tarred the bottom, boat souped the top and threw it in the water, where it remained in use for the next 5 years or so til I decided to pull it out (below) and rebuild it properly, as it leaked some at the ends where the bottom planks had shrunk.

http://pic3.picturetrail.com/VOL12/1104763/2595357/30544686.jpg

Guess what? Those planks had soaked up a goodly amount of water in all that time and those 14' beads of 5200 pulled out like clean, new rope.

It's a great construction adhesive under a house floor, but not a very good marine "glue" in my book.

[ 04-09-2005, 12:44 AM: Message edited by: Bob Smalser ]

[RonW]

Not to be rude, but there are some points that need clearified. 3m5200, pl adhesive WHAT? polyurethane glues.

3m5200, if you read the link that ray posted above, there is discussion on 3m5200 pulling loose from wet wood.This has been my experience too, I also found that when it dries, in about a week or so it sands and paints very well. But after a year or so the paint peels off of 3m5200, it is as if the product produces a oily residue later in life.The 3m5200 company techs would not give me a life span on this product. It is not a polyurethane glue, as the side of the tube says, it is a polyurethane formulation, so I take it that it has some little bit of polyurethane in it. P.L. is 100% polyurethane, big difference.And 3m5200 has never been used in the construction industry, it is too exspensive and quite frankly not up to the task.I do not use it any more at all.

P.l. what?, the OSI company that makes the pl products, which there are a couple dozen of, and each one is made for a specific task. Anyhow they named all their products starting off with the pl label. So you need to use the right one for the specific task it was designed for.I know there is confusion on this part. P.L.Premium is a fantastic wood glue, used properly. It is designed to be used as a thin-depending on what every one thinks thin is- glue line between 2 dry and clean pieces of wood. Not as fillets.
The guy at simplicity boats, I just shake my head at how stupid he is, obviously he has no wood working experience at all. To use this type of glue with glass tape to make fillets out of is just amzing to say the least.I am surprised it is doing as well as it is.He is even trying to make fillets out of a concrete sealant. But it sure wasn't intended for such a stupid purpose. I am not a epoxy fan, but if there is a good place for epoxy it is in making fillets.

Polyurethane glues, research the threads, a few months ago I put a link from the U.S. Forestry service where they did a polyuretnae glue test.
They used resorcinol as a comparison. Resorcinol is not cheap or easy to use, but probably the best wood glue that the general public can buy. Resorcinol does require very good fitting joints unlike epoxy that close is good enough along with a fillet or 2.
The bottom line of the test results where that on dry wood polyurethane glues actually superceeded resorcinol in sheer strength.On wet wood poly was weaker, but not by very much, and it doesn't pull off of wet wood (at all) let alone in a long strand like 3m5200 does.

If you have pl premium, not pl 400 or pl 200 I think you will be very happy with it if you use it right.It is a strong tough glue.

[Tom Lathrop]

Thanks for the info Ron. Can you repost the Forest Service link?

[NormMessinger]

Good, Ron. Thanks.

[Ken Hutchins]

Gotta love the info here on the forum, first lots of bad words about not using 5200 because it's permanent, impossible to remove etc. :rolleyes: , now Bob tells us it comes out like clean new rope. :confused: smile.gif :confused: smile.gif

[Bob Smalser]

Originally posted by Ken Hutchins:
Gotta love the info here on the forum, first lots of bad words about not using 5200 because it's permanent, impossible to remove etc. :rolleyes: , now Bob tells us it comes out like clean new rope. :confused: smile.gif :confused: smile.gif Thought I'd throw that experience in there before folks get too caught up in what a great "glue" poly sealant is. It's a sealant, not a glue....and my experience is when the wood soaks up to 25% M/C or above, it's still a good sealant but no longer a glue.

I wouldn't use PL Premium poly construction adhesive as anything but a sealant under marine conditions, either. I'll let somebody else accumulate the long-term marine experience with it while I use proven products, thanks.

But like I said, I think that'd all be OK in a riveted block.

Here's that USDA test on polyurethane glues - it's a bit out of date now on brands and types:

http://www.fpl.fs.fed.us/documnts/pdf1998/vick98b.pdf

And abstracts of some interesting discussion over the results:


Think we all can agree that resorcinol is our strongest wood glue, dry or wet, maybe not the easiest or most desirable to use in all situations, but still the strongest. That is why they used resorcinol as a comparison for polyurethane glues.

They used 2 woods, yellow birch and douglas fir.
On the d.f. in the dry test, the polyurethane had a sheer strength of 1200, while resorcinol had 900 lbs of sheer strength, poly had almost a 100% wood failure. In both cases more then resorcinol.

In the next 3 tests which all are wet tests including a boil test, it appears that poly falls way behind resorcinol. Resorcinol has about 2 times as much wood failure in d.f. and almost 4 times as much in yellow birch as does the poly.
Sounds convincing for the resorcinol, But hold it. Look at the sheer strength in the same tests, and this is where it gets interesting.

The poly failed at only about 10% less sheer strength then did the resorcinol.
So it would appear that poly is stronger then resorcinol in dry wood joints and about 90% as strong as resorcinol under wet wood conditions.
After all isn't the real test of a glue joint the actual lbs of sheer strength that it actually takes to rip the joint apart.

As for the greater difference in wood failure in wet wood for the resorcinol.When you think about it, resorcinol requires tight fits and tight clamping, and results in a 5 or 6 thousands glue line. Poly would have a 25 thousands glue line or about 5 times thicker glue line.It would be much easier for the glue line to fail with a much thicker glue line, but again bottom line is - what is the actual sheer strength to pull apart the glue line, and poly only has about 10% less strength then resorcinol in wet woods.

It would make sense that you use metal fasteners as well in wet conditions.

I looked in this site but, as of yet have not found a test comparing epoxy, it should be there somewhere and might be interesting as well to compare all 3 glues.

Durability, u.v., hot and cold resistance as well as life span and flexibility might be interesting as well. Resorcinol has a very long life. They claim the poly's do too.


1. The section on delamination suggests that poly is much more likely to delaminate under wet-dry cycling. Such wet-dry cycling is, of course, very common in boats.

2. In the tests I presume they used simple edge joints and that the glueline thickness was about the same for the various samples, rather than being thicker for poly.

3. I don't think you are correct in saying that metal fastenings would usually be used in wet situations. After all, this mast will almost certainly not have metal fastenings all over the place. More to the point (since a mast might not really be a wet situation in many cases), one of the most common uses for glue in marine situations is for laminating frames, stems, keels and other parts. In non-monocoque hulls especially, these parts may well have some fasteners in them (such as planking screws), but potentially not enough fastenings to fully hold them together. Even if there are enough, if they delaminate but don't disassemble that would still be highly undesirable. In a non-monocoque hull these parts are also very likely to see the regular wet-dry cycling that caused problems with the polyurethanes.




[ 04-09-2005, 10:36 AM: Message edited by: Bob Smalser ]

[Ken Hutchins]

Sorta explains why I use resorcinol, smile.gif except for big parts where wood movement is a problem, those places I use 5200. smile.gif

[RonW]

Well we all won't agree on what glue, wood, color or shape of boat. And that is a good thing (as martha would say) and if we did, it would be a pretty boring world. Wouldn't it be terribly if every one would only painted their boat white.

3m500, hey I liked 3m5200, but it does have problems. Besides being the only thing that I know of that is as gooey as butyl rubber, it will release from wet wood, it doesn't hold paint over a long time, and the 3m5200 techs play as dumb as a box of rocks when you ask a simple question like - what is the lifespan of the product.

Forestry test on polyurethanes, look at the charts at the bottom of the page, the charts that show actual sheer strength are pretty amazing. After all that is what you want to know isn't it, how much sheer strength it actually takes to tear apart the joint.On the wood rippage chart, in the dry soft wood it actually has more wood failure then resorcinol, but in the hard woods and wet woods, resorcinol has more wood rippage. But again look to see just what that means in actual sheer strength and remember resorcinol only has a 5 or 10 thousands glue line where a poly is probably 5 times that thick, probably about as thick as a tight epoxy joint.

The first time I used a polyurethane glue was 32 years ago in the construction business, think it was p.l.200 and just a couple of years later they came out with p.l. 400. I have never heard of any glue failures with the polyuretane glues. For boat building I am recommending P.L. premium.
Not the subfloor glues or concrete patch or gutter seal, and do not use it as fillets, which here is where epoxy is king.

Resorcinol- I warn caution on this glue, because of shelf life, 20 or 30 years ago all the hardware stores had the little blue cans of resorcinol, now very few will even know what you are talking about. I know for a fact that a local hardware store here has had one pack of resorcinol sitting on their shelf for about 5 years. It is covered in dust, and if they dust it off and someone buys it, they (should) end up with very unsatisfactory results. As I remeber, it
only has a 6 month to 1 year shelf life.
Some of the specialty resorcinol's that are manufactured for example for marine plywood, is made on the spot and and has as short as a 48 hour shelf life.

Thats my .02cents worth, and don't forget to use different colors of paint on your boat.

[RonW]

Being CRITICAL of polyurethane as well.

To add a couple of comments I also will criticise what I feel doesn't work.
Last fall it came to my attention that the OSI company which is here in Ohio and makes all the p.l. brands plus more, and is a subsidary of Sovereign chemical company, also starting producing a liquid in a bottle poly, kinda like gorrilla glue. Which I think gorrilla glue is the biggest advertising scam of the 20th century.

Anyhow they named it very briefly -what else- p.l. premium liquid, but that only lasted a couple of months. But still I tracked a bottle down, and it is being sold under the name of nail power. And the nail power glues are also made by osi and sold next to the p.l. brands at a slightly reduced price, maybe a marketing gimmick, or a slightly cheaper product.
But a 16 oz. bottle sells for $15, as compared to a tube of p.l.premium for $3. at 10.2 oz.

In testing the liquid variety, you are to dampen the wood as in using gorrila glue, I tried it damp and dry and My conclusions are that it is no where near as strong as the $3. a tube p.l.premium. I was sadly dissapointed, had hopes of it being stronger and easier to use. Other then the actual boat hull, think I would much prefer a brown carpenters glue, like tite bond or good old elmer's brown.

OSI seems to be very honest and forthright in their claims. There has been some discussion as to their poly window and door caulk. This is some neat stuff and works very well. Very strong grab and flexible, could easily replace 3m5200 at 1/4 the cost and probably a better product. OSI says on the tube it will last for 50 years, but they also says not to use under water. Which may not be a problem if used as a bedding compound and painted over, but maybe more clearification could be used on this limitation.

On the p.l. premium tube the only limitation is not to use below 40degrees. It is water proof, and I called osi and asked about using it on a boat hull below the waterline, they said no problem, just don't use it with temperatures below 40 degrees.It also states that it will last as long as the pieces glued together lasts. Now this is a lot of durability claims, maybe someone ought to glue two rocks together and send them to osi for a technical opinion on durability.

Personally, I can't imagine using a glue without fasteners, and that is why I could never ever build a stitch and tape boat.
Another added opinion.