Hello,
I'm in the process of building a pergola in northern Sweden. The horizontal beams will be made from double pressure-treated beams that will be glued and screwed together. I was planning to use PU glue that I already have, but I noticed that the minimum working temperature is 15 degrees. A quick Google search indicates that 15 degrees is quite normal for PU glue. I found one manufacturer that specifies 10 degrees.
The problem is that it's about 8 degrees during the day and barely above freezing at night. The weather forecast suggests it will continue like this. I would prefer to build now.
The question is, what happens if I go ahead anyway? I could possibly cover everything with a tarp at the end of the day and use some heat. It's unclear how warm it will get then and how long it takes after the first parts are glued.
Does anyone have any thoughts on this?
I'm in the process of building a pergola in northern Sweden. The horizontal beams will be made from double pressure-treated beams that will be glued and screwed together. I was planning to use PU glue that I already have, but I noticed that the minimum working temperature is 15 degrees. A quick Google search indicates that 15 degrees is quite normal for PU glue. I found one manufacturer that specifies 10 degrees.
The problem is that it's about 8 degrees during the day and barely above freezing at night. The weather forecast suggests it will continue like this. I would prefer to build now.
The question is, what happens if I go ahead anyway? I could possibly cover everything with a tarp at the end of the day and use some heat. It's unclear how warm it will get then and how long it takes after the first parts are glued.
Does anyone have any thoughts on this?
Then the glue was purchased. It ended up being a PU glue from Bostik, which is specified for temperatures down to 10 degrees. The forecasts are that it will be around 10 degrees during the day and cooling down to a few plus degrees at night. The gluing will probably take place in the afternoon, so it might not be a bad idea to cover the entire construction with a press when we're done and run a fan overnight.
How long is the curing time? If I remember correctly, when I glue-screwed my beams, it cured quite quickly. In a few hours. I had glue, it was like honey in consistency, and a spray bottle to add some extra moisture to the glue. Then I pressed the parts together with clamps and screwed them together. Then they were left to harden for a few hours. What's important is that you remove any excess glue. Otherwise, it is hopelessly difficult to remove it once it has fully cured. It becomes rock hard.
Sounds like PU-glue. The bottle says one day for full curing. Press time is 4-5 hours at 20 degrees. For me, the temperature will probably drop far below 10 degrees after maybe five hours.T tobbbias said:What is the curing time? If I remember correctly when I glue-screwed my beams, it cured pretty quickly. In a few hours. I had glue, it was honey-like in consistency, and a spray bottle to add some extra moisture to the glue. Then I pressed the parts together with clamps and then screwed them together. Then they sat there to harden for a few hours. What is important is that you remove any excess glue. Otherwise, it is hopelessly difficult to remove it once it has fully cured. It becomes rock-hard.
Yes, it's a hassle to work with. I have to glue my beams in place. The plan is to cut away the chamfer on the underside of the battens and sand away the excess after it has cured. The top side isn't visible, so the chamfer on the battens can remain. The gap between the battens will likely be full of glue after the excess has been sanded away.
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