[routafinger]

Not sure where to ask this question, so will start here. Mods please repost elsewhere if need be. Thanks.
I'm making a picnic table with pressure treated dimension lumber. The top will be made up of varying width sized 2x somethings. I have made a template to rout a pocket in one of the boards into which I want to permanently afix an aluminum plaque into. I have sized the pocket to be just a bit larger than the plaque to allow for any shrinkage or contraction of the wood. It would be flush with the top of the table.
My question is what would be the best adhesive to use to install it? I'm thinking maybe liquid nails or some other outside weather proof adhesive in a tube for a caulking gun. Mechanical fasteners or screws won't work, as I don't want to drill any holes in the plaque. I thought I could use what ever adhesive I decide on to fill the minute space between the plaque and the board. Otherwise, maybe some exterior silicon caulk? Any ideas to offer me? Thanks.

 

[Stick486]

PL Premium...
http://www.loctiteproducts.com/p/12...remium-Polyurethane-Construction-Adhesive.htm

note...
it will expand so weight down your plaque till the adhesive is cured....

 

[Semipro]

+1 with Stick ( construction grade adhesive)

 

[routafinger]

+1 with Stick ( construction grade adhesive)

Thanks for the quick replies. I haven't used the PL Premium before, so now I guess my questions would be how much it will expand, and how low will it take to cure? If I clamp the plaque to the board, will the adhesive expand up around the outside edge of the plaque? Then be easily cleaned off with a rag and a sharp chisel or putty knife? Should I "butter" the adhesive into one thin layer, or simply apply a bead to about half of the surface? Please bear with the questions. Thanks.

 

[Stick486]

held in place it won't expand much...
read the tube for cure time.....
MS cleans it up really well while it's wet...
dry it will shave/scrape easily..
one side application and more isn't better...

 

[JOAT]

Not a good idea, using some types of pressure treated wood.
Safety information about usage of treated wood - PTW-Safety

 

[hawkeye10]

Frank I would go with what Stick suggested. I wonder if a few holes should be drilled under the plaque to let water seep out. In the winter if water freezes and thaws that might be a problem. Just a thought I had.

 

[Cherryville Chuck]

No silicon, it will fail within two years my guess. I also recommend PL, either 400 or Premium, both are waterproof. It will expand very little. Rut a small block of wood on top of the plaque. Put similar blocks on either side of it. Lay a board on top. The weight of the board is probably enough.

 

[routafinger]

Not a good idea, using some types of pressure treated wood.
Safety information about usage of treated wood - PTW-Safety

A good point, but I think most of the pressure treated lumber sold today isn't nearly as deadly as the older lumber preserved with arsenic.

 

[routafinger]

held in place it won't expand much...
read the tube for cure time.....
MS cleans it up really well while it's wet...
dry it will shave/scrape easily..
one side application and more isn't better...

Thanks for all of the info.

 

[Mycrossover]

A good point, but I think most of the pressure treated lumber sold today isn't nearly as deadly as the older lumber preserved with arsenic.

Not quite as nasty but I wonder how effective any adhesive would be on the surface of pressure treated lumber. I believe the pressure treatment does not go all the way through so your routed pocket might get down to bare wood. In that case the above reccomendations would work. I would take a piece of scrap pressure treated and a piece of scrap metal and make a test bond.

Sent from my SM-G900V using Tapatalk

 

[Knothead47]

I would question the effectiveness of any adhesive on PT wood. My son-in-law's deck is painted and the paint is coming off. Would adhesive behave in the same manner?

 

[harrysin]

Here in Australia I would, and have used construction grade liquid nails, I've used it on wood, bricks, concrete and Polystyrene plus materials that I've long since forgotten.

 

[DaninVan]

The Construction Adhesives are absolutely the correct glue to use with wet, icy, pressure treated lumber. It's pretty much the ONLY stuff that works under those conditions.
Been using it for at least 30+ years and I don't recall ever having it fail; it doesn't work like regular wood glues.
In Frank's situation there's no stress on the plaque once it's installed, so compared to laying a T&G plywood deck down in the rain or below freezing weather, this is a walk in the park.
As for PT being unsuitable for a picnic table, how many of you put plastic in your microwave ovens, or eat fruit from the supermarket?
If you want to worry about ingesting toxins, those two are a good place to start... *

"These products undergo extensive testing for so-called “safety” issues that must be done before receiving a label approved by Environmental Protection Agency. So our EPA is saying that this product has met its tolerances of “safety” (the agency does not like you to use the word “safe” in instances like this because it does not guarantee any pesticide is “safe”) and has approved this label. The product is supposed to be at such low levels in the plant that the government considers it safe to eat."
https://www.reviewjournal.com/life/...ecticide-affects-entire-tree-including-fruit/

 

[routafinger]

Thanks again for all of your replies, and heading me in the right direction. It looks like the PL Premium is the best product for my application. A phone call to Loctite yielded the following info: the product would work well on pressure treated lumber if it was allowed to dry for about 6 mos before application. Evidently the wood is too wet for the best bond, and the bond might not be as strong. So I'm wondering if I could hurry the drying time in the pocket by using a heat gun? I really didn't want to wait that long before installing the plaque. I'm thinking that I'll try that, and if it doesn't work, I'll just have to wait. Comments? Thanks.

 

[DesertRatTom]

I'd never trust the pressure treated wood on the top. Consider using something else up top with the treated stuff forming the legs and support. If there's a chance someone will sit on the seat in a wet bathing (or birthday) suit, a chemical leach might at least become irritating. It's a picnic table, people use them that way. The problem with insects is usually at the point of wood contact with the ground so the treated stuff doesn't have to include the top. If I thought a table was treated on top, I would find another table. Just sayin'.

 

[JOAT]

I'd never trust the pressure treated wood on the top. Consider using something else up top with the treated stuff forming the legs and support. If there's a chance someone will sit on the seat in a wet bathing (or birthday) suit, a chemical leach might at least become irritating. It's a picnic table, people use them that way. The problem with insects is usually at the point of wood contact with the ground so the treated stuff doesn't have to include the top. If I thought a table was treated on top, I would find another table. Just sayin'.

With you on that. Many, many, years ago, my old man made a picnic table framed with square tubing. The top and seats were about 2X12, varnished. That thing is probably still in use today, it was made that well. Not certain, but likely there are plans out there on-line, somewhere.

Took a quick look, found this. https://bradgreenwooddesigns.com/portfolio-items/picnic-table/ Not sure if they are selling kits, plans, or tables. But if I wanted to make one it would be plenty simple enough to make one just from the picture. Not the same style as my old man's table, but there are plenty more sites out there with kits, plans, et al.

 

[Stick486]

I would question the effectiveness of any adhesive on PT wood. My son-in-law's deck is painted and the paint is coming off. Would adhesive behave in the same manner?

PL premium is designed for PT...

 

[Stick486]

Here in Australia I would, and have used construction grade liquid nails, I've used it on wood, bricks, concrete and Polystyrene plus materials that I've long since forgotten.

Harry..
LN is some pathetic junk/trash/garbage...

 

[Cherryville Chuck]

The old treated lumber was CCA which stands for Chromated Copper Arsenate. The replacement is ACQ which stands for Alkaline Copper Quaternary (ammonium compound) which is water based. Preservers don't like treating very dry lumber because dry wood soaks up more of the treatment compound which costs them more money. Because of that some of the PW you get has pretty high MC.