Teardrops n Tiny Travel Trailers

So, I can get LOSP H3 Pine for framing the floor.
I believe that stands for Light Organic Solvent Preservative, with H3 meaning suitable outdoor above ground use.
The question becomes, will the mix work on it, and will sika 252 polyurethane or sikabond tech grip stick to it?

I would reckon yes and yes but why not grab a few small pieces and try it out? I have even stuck magnets to varnished plywood with Sika polyurethane glue so I would be surprised if it won't work.

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...meaning suitable outdoor...

Doesn't that infer that it's not suitable for a living space?



Tony

edgeau wrote:I would reckon yes and yes but why not grab a few small pieces and try it out?
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Exactly the conclusion I came to in the shower this morning!

tony.latham wrote:

...meaning suitable outdoor...

Doesn't that infer that it's not suitable for a living space?



Tony

It is what they use to build frame houses here, so its behind just about every piece of gyprock (sheetrock?) put up in the last 20 or 30 years.
So I thought it might be good for underneath the floor sheets.

It is what they use to build frame houses here, so its behind just about every piece of gyprock (sheetrock?) put up in the last 20 or 30 years.

Gotcha.

We call 'em studs. Seriously.

T

Copied from data sheet.
Areas of Application
Sikaflex
®
-252 is suitable for
structural joints that will be
subjected to dynamic stresses.
Suitable substrates include wood,
metals, particularly aluminum,

tony.latham wrote:

It is what they use to build frame houses here, so its behind just about every piece of gyprock (sheetrock?) put up in the last 20 or 30 years.

Gotcha.

We call 'em studs. Seriously.

T

So do we.
The vertical sticks anyway.
The little horizontal ones between the vertical studs are noggins

twisted lines wrote:Copied from data sheet.
Areas of Application
Sikaflex
®
-252 is suitable for
structural joints that will be
subjected to dynamic stresses.
Suitable substrates include wood,
metals, particularly aluminum,

Yes I have that data sheet. It was reading it that convinced me to go with the 252. It had the highest bond strength, the highest shear strength, best water resistance, etc. And a wide range of suitable substrates.
It's the oily feel of the preservative that has me worried.
I'll run some tests and report back for the benefit of all of us.

Further research:
The timber was "tanalised" at plant #511 with azole preservative #64 to durability class H3 - outdoor above ground exposure.


I cut 2 inches off the end of a stick. The piece promptly split in two. Since I don't really want to open a $33 tube of sika flex 252 until I'm ready to go, I thought I'd start by gluing this two inch piece back together with the Sikabond Tech Grip polyurethane. This stuff seems the equivalent of Gorilla Glue polyurethane.
Apply to one surface sparingly, it said.


Then I clamped it lightly together, at which point it became obvious that Sikabond has a different interpretation of sparingly than I do, as glue squeezed out every surface. This bottle of glue is going to go a long way.


After an hour the glue has begun to froth a bit. This is "normal" for polyurethane I have read.
I intended to dampen the surface I didn't apply the glue to, but forgot in my haste.
I blame the 12 hour day at work. Still the fact that it is frothing suggessts that the glue is doing what it should.

I'll give it the recommnded 24 hours, sand the surface of the glued 2 inch piece and the same size surface area on the long stick it came from and see if I can glue the two pieces back together on the surfaces that always feel funny to me.
Then I'll give that 24 hours to dry. This is Monday night, 10pm. By about Wednesday night, 10pm, I expect to find out how well Sikabond Techgrip adheres to the outer surfaces of treated timber and also to the interior of treated timber.

What kind of wood is that? I don't recognize the grain.

So you guys use treated wood for studs? Termites?



Tony

It's pinus radiata.
Very common plantation timber here.
Called Monterey Pine in California, where it came from.
Wikipedia says it is the most widely planted pine in the world.
I must admit this particular stick has a fairly atypical grain appearance on the face that has the stamp on it, but certainly looks more normal on the other surfaces.
Some parts of Australia aren't well endowed with native forest.
Sustainable supply of timber requires plantations.
The quick growing softwoods need treatment for outdoor use and, yes, the termites here are savage man.
Once we decided Aldrin and Dieldrin were too nasty for treating your house, the substitute chemicals weren't as effective and treated wood became necessary.

So I went straight to the shed when I got home from work.



The squeezed out glue was opaque, hard, and seemed to cut off easily with a wood chisel.
I wanted to be at least a little bit scientific, and measure the breaking strength somehow.
So I decided to mount the test piece in the vise and use a torque wrench to twist it.
To get a grip I used a three-legged oil filter wrench spaced out with a bit of square tube.
Started off at 10 ft-lbs. Wrench went click.
Up to 20 ft-lbs. Click. And so it went.

I was really starting to lace into it at 60 ft-lbs of twiisting force when my son said, "you're bending the filter wrench"
So, at some point north of 50 ft-lbs the filter wrench was weaker than the timber and the glue.
Called it a day and said "Strong enough for me".
Joint area 35mm x 56mm.

So then I scrubbed a wide face on the glued piece with a wet rag. Did the same on the end of the long stick it came from, let it dry a moment and smeared on some more TechGrip.
Lightly clamped, we'll see how the gluing of un-sanded surfaces of LOSP treated pine goes tomorrow night.

I love it - the glued joint is stronger than the tools meant to break it! Up here in QLD I have never needed to wet the wood as we are always so humid. I even have to put the bottle in a snap lock bag once opened or it goes off before I have used it all

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MickinOz wrote: Since I don't really want to open a $33 tube of sika flex 252 until I'm ready to go,

Guess Amazon prime is no good there!

twisted lines wrote:

MickinOz wrote: Since I don't really want to open a $33 tube of sika flex 252 until I'm ready to go,

Guess Amazon prime is no good there!

Sure it is. - $37 per tube off there though.
If you buy a case of 24 its cheaper of course.
Bear in mind, too, that $33 Australian is "only" $23 US

edgeau wrote:Up here in QLD I have never needed to wet the wood as we are always so humid.

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First bond I did not wet it, it was a clean fresh break that didn't need cleaning. It set fine overnight.

For the second test, I scrubbed with a wet towel just to clean the timber which has been lying around for a while.
It certainly set quicker this time, though.
Which appears to mean you can actually have some control over the set time.

I really like this glue. It swells a bit, presumably because of the water uptake, so good gap filling, and you really do need to use it very sparingly, which makes it much more cost effective.