Re: [bolger] Re: PL Preimum
Here in Spain we don´t have the same brands as you have, so I haven´t
had a chance to try PL premium, but I have used other polyutethane
glues.
The one I have used most extensively is Quilosa 1K ( monocomponent)
exterior / marine polyurethane glue.
While it does a fine job, I have found that in places where I had
glued a wood part to a ply sheet, the swelling of the wood started to
crack the glue joint.
This was under the waterline areas of a dry sailed boat, where the
wood absorbed more water through the paint. It was painted with a
water based exterior acrylic paint that "regulates moisture". I guess
the ply only absorbs up to the first glue layer, while the wood will
take in a lot more.
This particular glue foams where it runs out, so i imagine it will
also do so in the joint, where I don´t think it helps any.
This glue is fast. 2 Hrs. for handling, 12 Hrs. for strength, 24 for
full cure. It is convenient, easy to use.
OTOH, it is more expensive than epoxy, less strong and durable, and
has a shelf life of 8 months.
I guess it is a question of carefully choosing application parameters.
Juan.
had a chance to try PL premium, but I have used other polyutethane
glues.
The one I have used most extensively is Quilosa 1K ( monocomponent)
exterior / marine polyurethane glue.
While it does a fine job, I have found that in places where I had
glued a wood part to a ply sheet, the swelling of the wood started to
crack the glue joint.
This was under the waterline areas of a dry sailed boat, where the
wood absorbed more water through the paint. It was painted with a
water based exterior acrylic paint that "regulates moisture". I guess
the ply only absorbs up to the first glue layer, while the wood will
take in a lot more.
This particular glue foams where it runs out, so i imagine it will
also do so in the joint, where I don´t think it helps any.
This glue is fast. 2 Hrs. for handling, 12 Hrs. for strength, 24 for
full cure. It is convenient, easy to use.
OTOH, it is more expensive than epoxy, less strong and durable, and
has a shelf life of 8 months.
I guess it is a question of carefully choosing application parameters.
Juan.
Make sure all is clean. Only need to clamp lightly. Moisten wood a bit
beforehand (this is critical, I think). Let it set for a long time,
maybe a week? I like PL, but I'm not sure I would use it in a place
under constant tension as I have had one failure on the end of a
gunwhale, after a long time. Make sure you are using PL Premium
Construction Adhesive and not PL 400 or some other weird stuff. I
understand that the concrete adhesive is ok, but I don't know anything
about it.
Lincoln Ross
beforehand (this is critical, I think). Let it set for a long time,
maybe a week? I like PL, but I'm not sure I would use it in a place
under constant tension as I have had one failure on the end of a
gunwhale, after a long time. Make sure you are using PL Premium
Construction Adhesive and not PL 400 or some other weird stuff. I
understand that the concrete adhesive is ok, but I don't know anything
about it.
Lincoln Ross
>Donald E. Johnson wrote:
>
>I've seen so many good reviews of PL Premium that I decided to give it a try. The
>price is great and the convenience of a strong glue that doesn't require mixing is very
>appealing.
>
>I used it to glue a piece of quarter inch luan to some half inch ply, on a curve. The
>luan was thus being tortured into shape.
>
>I put down a nice bead of PL and clamped the luan into position. The clamping was
>set up a bit loose so as not to squeeze out too much of the glue, like I would do for
>epoxy. The next day, I took off the clamps and after a minute or so, the luan
>returned to an almost straight shape, pulling out from the PL. (It was the PL that
>failed, not the ply.)
>snip
>What did I do wrong with the PL? Should this stuff be clamped tightly like yellow
>glue instead of treating it like epoxy? Could I just have a bad tube?
>
>
>-Don Johnson
>
I like PL for lots of reasons and in *some* applications I feel it's
superior to epoxy. But it isn't epoxy. Having said that...
Check the directions on the tube and you'll see you need to fit
pieces together, remove to let the glue outvent (or whatever you call
it) for 10 minutes or so - a good time to check the gluing surfaces
for coverage and even contact and make sure there's no starvation -
then re-ttach with some pressure, clamps or screws. I do a "belt and
suspenders" with PL and always make sure to have some kind of
mechanical attachement, if possible. To date I've yet to have a
functional failure even on non-mechanically fastened pieces.
As for T fits (say bulkhead to hull side) I would never use PL alone.
I use drywall tape and do a proper joint just like you do with epoxy.
If it's well coated - but not overly coated - I've had good results?
As good as epoxy? Probably not but no failures to date.
As for your tortured lauan test - if strength in this area is REALLY
important, I probably wouldn't use just a bead of PL, maybe tape and
PL.
In my experience PL needs at least 24 hrs to really harden up, my
evening gluing is still a bit green the next morning.
BTW - I don't need to do any "steenking" torture tests, I just built
a boat out of PL and tortured it.
Bryant
superior to epoxy. But it isn't epoxy. Having said that...
Check the directions on the tube and you'll see you need to fit
pieces together, remove to let the glue outvent (or whatever you call
it) for 10 minutes or so - a good time to check the gluing surfaces
for coverage and even contact and make sure there's no starvation -
then re-ttach with some pressure, clamps or screws. I do a "belt and
suspenders" with PL and always make sure to have some kind of
mechanical attachement, if possible. To date I've yet to have a
functional failure even on non-mechanically fastened pieces.
As for T fits (say bulkhead to hull side) I would never use PL alone.
I use drywall tape and do a proper joint just like you do with epoxy.
If it's well coated - but not overly coated - I've had good results?
As good as epoxy? Probably not but no failures to date.
As for your tortured lauan test - if strength in this area is REALLY
important, I probably wouldn't use just a bead of PL, maybe tape and
PL.
In my experience PL needs at least 24 hrs to really harden up, my
evening gluing is still a bit green the next morning.
BTW - I don't need to do any "steenking" torture tests, I just built
a boat out of PL and tortured it.
Bryant
--- Inbolger@yahoogroups.com, "Donald E. Johnson" <don@f...> wrote:
>
> I've seen so many good reviews of PL Premium that I decided to give
it a try. The
> price is great and the convenience of a strong glue that doesn't
require mixing is very
> appealing.
>
> I used it to glue a piece of quarter inch luan to some half inch
ply, on a curve. The
> luan was thus being tortured into shape.
>
> I put down a nice bead of PL and clamped the luan into position.
The clamping was
> set up a bit loose so as not to squeeze out too much of the glue,
like I would do for
> epoxy. The next day, I took off the clamps and after a minute or
so, the luan
> returned to an almost straight shape, pulling out from the PL. (It
was the PL that
> failed, not the ply.)
>
> I scraped and sanded off the remaining PL, and re-glued the piece
with epoxy. I took
> off the clamps this morning and it's solid.
>
> I also made up a test, just gluing a piece of scrap half inch ply
to another. This
> wasn't clamped at all. I just put a thick bead of PL on the end
grain of one piece and
> stood it on the other, using a third piece to hold it stable.
This also set overnight
> (probably 16-20 hours). It took almost no effort to break this
bond. (Hot melt glue
> after about two minutes is stronger.)
>
> What did I do wrong with the PL? Should this stuff be clamped
tightly like yellow
> glue instead of treating it like epoxy? Could I just have a bad
tube?
>
>
> -Don Johnson
I've seen so many good reviews of PL Premium that I decided to give it a try. The
price is great and the convenience of a strong glue that doesn't require mixing is very
appealing.
I used it to glue a piece of quarter inch luan to some half inch ply, on a curve. The
luan was thus being tortured into shape.
I put down a nice bead of PL and clamped the luan into position. The clamping was
set up a bit loose so as not to squeeze out too much of the glue, like I would do for
epoxy. The next day, I took off the clamps and after a minute or so, the luan
returned to an almost straight shape, pulling out from the PL. (It was the PL that
failed, not the ply.)
I scraped and sanded off the remaining PL, and re-glued the piece with epoxy. I took
off the clamps this morning and it's solid.
I also made up a test, just gluing a piece of scrap half inch ply to another. This
wasn't clamped at all. I just put a thick bead of PL on the end grain of one piece and
stood it on the other, using a third piece to hold it stable. This also set overnight
(probably 16-20 hours). It took almost no effort to break this bond. (Hot melt glue
after about two minutes is stronger.)
What did I do wrong with the PL? Should this stuff be clamped tightly like yellow
glue instead of treating it like epoxy? Could I just have a bad tube?
-Don Johnson
price is great and the convenience of a strong glue that doesn't require mixing is very
appealing.
I used it to glue a piece of quarter inch luan to some half inch ply, on a curve. The
luan was thus being tortured into shape.
I put down a nice bead of PL and clamped the luan into position. The clamping was
set up a bit loose so as not to squeeze out too much of the glue, like I would do for
epoxy. The next day, I took off the clamps and after a minute or so, the luan
returned to an almost straight shape, pulling out from the PL. (It was the PL that
failed, not the ply.)
I scraped and sanded off the remaining PL, and re-glued the piece with epoxy. I took
off the clamps this morning and it's solid.
I also made up a test, just gluing a piece of scrap half inch ply to another. This
wasn't clamped at all. I just put a thick bead of PL on the end grain of one piece and
stood it on the other, using a third piece to hold it stable. This also set overnight
(probably 16-20 hours). It took almost no effort to break this bond. (Hot melt glue
after about two minutes is stronger.)
What did I do wrong with the PL? Should this stuff be clamped tightly like yellow
glue instead of treating it like epoxy? Could I just have a bad tube?
-Don Johnson