Spray Adhesive
Overview
I remember years ago there was a show here in the UK about art for children. Tony Hart, the presenter, would draw a gorgeous drawing and then apply it to a background and put it on the wall as if by magic. It was a few years later that I realised he was using spray adhesive. Spray adhesive is a miraculously versatile way of gluing very light things to surfaces.
It's worth bearing in mind that the term spray adhesive covers many different types of compound. The common characteristic is that all these compounds can provide an aerosol when delivered through a pressurised can.
However, the one characteristic they all have is the ability to make a surface adhesive without having to touch it or to layer it or to manually scrape down the glue onto the surface. That allows spray adhesives to be used in very delicate and finessed applications. Ideally you don't want to touch the surface that the spray adhesive lies on at all. You stand back, you spray it on and then you lay it on the surface you want to bond to. With a small and even amount of pressure for a short period of time, you have a bond.
Because they're so versatile they can be used for a wide range for purposes from simple adhesive to more complex compounds, which are essentially layers of rubber that can be laid down in sheets.
What jobs is this good for?
Because there can be a wide range of compounds that call themselves spray adhesives, the jobs that they're good for is more nuanced than for other adhesives. I'll go into more detail in this guide but in general they can vary in their resistance to water, temperature, heat, pressure and bonding strength. However, generally speaking these types of adhesive are used where a very clean layering of adhesive is required. So if you think back to the use of PVC glue at school perhaps, you may remember scraping it down with the pallet knife squeezing it down with your fingers. It gets quite messy. It gets bubbly. It's not a very good result. However, with a spray adhesive you spray it down from a distance of 4 to 6 inches, lay it on the piece of paper, and it's good to go.
Therefore, typically this type of glue is good for the likes of collages arts, crafts scrapbooks and is used widely in marketing. Where the production of mood boards on soft board needs to look professional and unblemished.
So if you want a fine finish that isn't particularly sticky then spray adhesives is the thing.
What's not that good for?
Spray Adhesives aren't the best for your lung health. Spraying adhesive aerosol into the environment in which you're also breathing may not be the best idea. Now I'm not saying that these are dangerous to use. They're used very widely without problems. However, you need to be careful where and when you use them and ideally use them in a well ventilated space. If you have a project that you use a spray adhesive on say for 10 or 15 minutes, the space that you're working in will get to the point where there's as much adhesive in the air than on the canvas you're sticking.
They're also not that good for the environment. Aerosols plus the various solvents that required to make the adhesive into an aerosol are not friendly chemicals and in some cases can actually be quite poisonous.
The low bonding strength isn't necessarily a problem because these are going to be used for jobs that require fine finish and not necessarily a strong bond. And so if you take suitable precautions while using them, they can give you a very fine and polished result.
How to use
Make sure you're in a well ventilated space, preferably with a mask, and you lay out the flat surface that you want to adhere to. You then spray evenly. I've always found that being very conscientious in the spring movement helps. Imagine yourself as one of these car manufacturing robots that spray paint cars going from side to side at an even pace and try not to overlap on the areas that you're bonding. When you get to the point that you've covered the area, lay down the other bonding sheet to it and apply some slight pressure, but be careful with this because the end result is meant to be immaculate and applying pressure may not be immaculate. I've always found placing a rather heavy book on top helps.
The drying and curing time can vary immensely. This is because the compounds can vary immensely. I'll go into this in more detail in the glue guides, but it can be anything from a few minutes to a few hours or even a day.