Project help?

[Wayne Smith]

I'm in the process of building a sandbox for the grandkids in NC. It was LOML's idea! Anyway, picture 4/4 white oak planks about 15" wide and five feet long. Rough cut box joint ends - 2.4" cuts. I'm building seats for each of the 4 corners.

I know Tightbond I, II, and III. What I don't know is the best outdoor gap filling glue. Something that will hold it together but still move with the wood. Tightbond is great indoors but is hard and won't move with the wood.

It's currently dry assembled in the back yard, the seats made, glue blocks screwed to the seats but not fitted or glued yet. In two weekends we will be carrying the pieces down to NC and assembling it there. Our son is in charge of filling it!

So what is the best outdoor gap filling construction adhesive?

[William Yanda]

Goop, really, the shoe fixer stuf Goop. I used to know the chemical formulation. Or for the size project you have, Liquid Nails. It comes in several varieties and the wood will separate before the glue joint.
Hope you have lots of coyotes to keep the cat population down. Seems the felines really like sandboxes for a place to do their business.

[Wayne Smith]

Does Liquid Nails still come in one formulation? I haven't used it in years. I've used Goop for shoe repair for years also. You are right, I'd prefer something in a tube that can be pumped out.

[WebMonkey]

flex seal/glue/tape/adhesive

'even works under whuuuaaater'

;)

[Der Gebirgsjager]

Gorilla Glue?

[country gent]

Ive been using the tite bond 3 in the garage for boxes and odds and ends. Its listed as water proof not water resistant. It does give a very good bond when clamped properly. The old foaming gorilla glue is good also but a pain cleaning the foamed out in the joints. A sharp chisel works best.

A little tip sand and radius all edges to prevent splinters, Also a good finish on the wood helps here. Consider a roof or umbrella mount to help prevent sunburns on young skin.

When I built my kids sand box it was 4 x 8 with a peaked roof. I finished the box seats and uprights with a 2 part marine epoxy paint. This made a very tough coating that helped prevent splinters and protected the wood from moisture in the ground and sand very well. It held up very good.

Once you put up a sand box every cat in the neighborhood will find it LOL. I used a white paint as it dosnt get as hot and the brightness tends to keep bees from nesting under the roof.

[Conditor22]

How are you fastening the ends together? predrilled lag bolts (or big screws) and washers

when I was still in the industry I was a big fan of

OSI QUAD Advanced Formula 10 fl. oz. White #001 Window Door and Siding Sealant VOC (choose the color you want)
https://www.homedepot.com/p/OSI-QUAD-Advanced-Formula-10-fl-oz-White-001-Window-Door-and-Siding-Sealant-VOC-1642487/203357966

[Mk42gunner]

Thinking back to the sandbox Dad made for my brother and I, it was a simple open bottomed square made from 1x12's with seats nailed at each corner. 2x4 uprights at the corners and a couple of sheets of plywood for the flat roof.

He painted it white and it lasted for years. 500 pounds of sand from the lumber yard every few years sure gave us a lot of fun.

I'm sure the cats liked it, but back in the late 60's-70's we didn't worry about stuff like that, and we lived through it. Drank from the garden hose too.

Robert

[poppy42]

+1 on the gorilla glue. It’s an Apoxsee glue that’s activated by moisture when it cures you ain’t pulling it apart and it does expand!

[Wayne Smith]

Yes, Gentlemen, Gorilla Glue and Tightbond work well where you do not have to account for wood movement. I cut 2.4" cutouts one inch deep on the ends of the boards, so they fit together like a box joint. I had it put together and it was a little loose, it has rained for three days and it is so tight I'll have to let it dry a few days to knock it apart to get it in the car. So I will have to deal with wood movement.

I have corners numbered and seats numbered to the corners. Today I screwed and glued the seat glue blocks to the seats. Marked the sides where I have to sand off a little finish so glue will hold.

I was originally planning to use a screw/dowel combination but LOML thought it ought to be deeper - and that added enough weight so that would not be reliable. I even have some African Blackwood dowels turned to fit 3/4" holes - but that's not to be.

[Handloader109]

I'd break down and buy some 90 degree steel angle brackets and put one or two in the four corners. That will hold it together way better than any glue outside in the elements.
And I'd for sure use screws on any seat parts. Glue is fine indoors, but will fail outside. BTW, liquid nails has numerous varieties for sale. And they work well at filling gaps.

[samari46]

Built a 8'x8' planter out of pressure treated wood. That was some years back. Used the galvanized brackets and tapcon screws 3" long. Planter is about shot. However both the brackets and screws are doing good. Wondered why the wood rotted out and remembered that when growing stuff it was watered every day. On the other hand built a picnic table over 25 years ago and stained it. Actually had to take it apart so the movers could pick it up and put it in the trailer. Reassembled it and still one can stand on the seats and I dare anyone to even try to move it. Still under a covered overhang next to the house. Heat and humidity but no direct exposure to water. Frank

[David2011]

I’ve used Titebond for years for RC aircraft because it’s more flexible than most other wood glues. Titebond III is water/weather proof. You might get an opinion from Franklin regarding the suitability of Titebond III for your application. If they say it’s not suitable I think I would lean toward using stainless steel or silicon bronze screws along with proper drilling and countersinking. Those alloys will prevent iron sickness from damaging the wood.

[Wayne Smith]

Yes, all hardware is SS, and I ordered some corner brackets yesterday. Thanks for that idea, I hadn't thought of them. I also want to avoid the different metal bielectric problem, so everything is SS.

[fcvan]

When I first moved the family to Colorado my wife wanted a deck/porch by the front door. I used pressure treated for the posts and under supports. I used Trex boards to the decking. Then the wife suggested I build a sand box for our 2 y/o grandson. We put a box on the deck for storing sand toys, and she bought a cast iron and wood park type bench.

The Trex boards are easy to sweep the snow off, no splinters, no degradation. Deck and sandbox are on the north side and never see any sunshine. Later, she wanted me to poor concrete between the front door walk so now that is a 8 x 20 something concrete deck. Folks in Colorado use their front yards, neighbors always stop and say hello, far more friendly than California where we grew up. Other neighbors have put in decks and patio furniture since we moved there.

I think she spends more time on that bench than the other outdoor furniture she purchased, like patio glider and seating chairs. I think the local bears enjoy the sandbox more than our grand kids do. Sow with cubs, catch them all the time on the security cameras. No cats try to use the sandbox, coyotes and foxes keep the cat population down. I've got feral cats that hang out under the front porch at the California house, PITA.