by wefalck » Tue Aug 03, 2021 10:16 am
We shouldn't confuse vaindioux, but one could write books (and they do exist) about (industrial) glueing technology. The point is to understand some basics in order to not become frustrated.
Not only the materials to be joined are important, but also the form and extent of the joint and how the glue/cement can be applied.
There is a huge difference between laminating a thin sheet of styrene with CA onto a piece of wood and trying to cement a protruding styrene piece with a relatively small footprint to it with CA. CA as such is quite brittle an when levering at a protruding piece, the joint will likely separate, because the CA either peels off the styrene or the CA in itself will break.
Using a contact cement that due to its content of solvents will also attack the styrene to some extent will result in a stronger bond. In addition, many contact cements stay somewhat elastic, resulting in a more shock-resilient bond.
It is helpful to visualise some basics of glued joints. The glue/cement can have the effect of locking two pieces together, it can form a chemical bond with the pieces, or there can be simple physico-chemical interaction:
When you glue wood to wood with PVA, you lock the two pieces together, because the glue keys into the porous wood surface. The same happens with CA, but CA being brittle, the joint is quite easily separated by knocking the pieces apart.
When you cement metal to other materials, then on the side of the metal there will be only a physico-chemical interaction, as metals do not react with any solvents.
Liquid CA can be very useful for joints, where the geometry provides the main resistance, say when cementing metal spigots into holes. In general it is a good idea to create interlocking joints, also with the help of a third element, such as a dowel (wood, metal pin, styrene rod).
I think I rather stop here, but the main point was that CA has its applications, but is not the 'one-size-fits-all' solution.
We shouldn't confuse [i]vaindioux[/i], but one could write books (and they do exist) about (industrial) glueing technology. The point is to understand some basics in order to not become frustrated.
Not only the materials to be joined are important, but also the form and extent of the joint and how the glue/cement can be applied.
There is a huge difference between laminating a thin sheet of styrene with CA onto a piece of wood and trying to cement a protruding styrene piece with a relatively small footprint to it with CA. CA as such is quite brittle an when levering at a protruding piece, the joint will likely separate, because the CA either peels off the styrene or the CA in itself will break.
Using a contact cement that due to its content of solvents will also attack the styrene to some extent will result in a stronger bond. In addition, many contact cements stay somewhat elastic, resulting in a more shock-resilient bond.
It is helpful to visualise some basics of glued joints. The glue/cement can have the effect of locking two pieces together, it can form a chemical bond with the pieces, or there can be simple physico-chemical interaction:
When you glue wood to wood with PVA, you lock the two pieces together, because the glue keys into the porous wood surface. The same happens with CA, but CA being brittle, the joint is quite easily separated by knocking the pieces apart.
When you cement metal to other materials, then on the side of the metal there will be only a physico-chemical interaction, as metals do not react with any solvents.
Liquid CA can be very useful for joints, where the geometry provides the main resistance, say when cementing metal spigots into holes. In general it is a good idea to create interlocking joints, also with the help of a third element, such as a dowel (wood, metal pin, styrene rod).
I think I rather stop here, but the main point was that CA has its applications, but is not the 'one-size-fits-all' solution.