Varnish dissolving glue?

Michellenman

I've recently started making bits and bobs, mostly it's glue plastic to metal or wood to metal. The glue I'm using is the hot glue gun sticks, the problem is that once I've made my piece, I go to varnish it (a few days later) using an acrylic varnish, and after a few days the glue becomes tacky and stretchy again, instead of being hard and dry. Anyone have any ideas how I can remedy this? I can't change the type of glue I'm using and I just bought like 50 glue sticks, but would a change in the varnish help? If so, what type of varnish should I swap to?

Thanks in advance

Michelle

artieanna

You are using a solvent varnish so its the solvent which are melting/softening the plastic of the glue (white spirit would do the same). Try and source some water based varnish suitable for plastic its used in theatre etc.

I don't know where you can get it off hand but try ebay, large hardware stores, art craft shops etc

Michellenman

artieanna wrote: »

You are using a solvent varnish so its the solvent which are melting/softening the plastic of the glue (white spirit would do the same). Try and source some water based varnish suitable for plastic its used in theatre etc.

I don't know where you can get it off hand but try ebay, large hardware stores, art craft shops etc

Ah I see! Thanks I'll have a browse around stores and see what I can find. Thanks again!

Michellenman

So I legged it up to Inspiring Ideas today and it turns out I've been using a water based varnish all along, it's this one below. Galeria Acrylic mediums, gloss varnish.



Should I try a non-water-based varnish instead so?

TreasureBin

I'm surprised you're having that reaction with acrylic varnish - I think the previous reply about solvent-based varnish is correct so I don't think there's any point trying that.

Are you deliberately applying varnish to the glue (and if so, why), or is it just not possible to avoid the glue when applying the varnish?
I wonder if you could try applying a VERY light coat or two of acrylic spray varnish first to seal off the glue, then brush on layers of your acrylic varnish afterwards.

What kind of glue sticks are you using?

Michellenman

I'm avoiding putting the varnish along the back where the main gluing part is, but there is a little glue between the pieces which the varnish will touch because it will drip down.



One like this is the main problem. It's the glue that is between the dominos that seems to be affected the worst.

I bought some regular (non water-based) varnish today, I'll try that and just apply it to the top and try to be as careful as possible.

The glue sticks I used are the stick it hot melt glue gun sticks (these) but I ran out so I'm using these ones I picked up on ebay. I haven't tried to varnish anything I made with the ebay ones yet though.

TreasureBin

I've done a bit of research on Wikipedia and eHow, and it seems that some glue sticks have an acrylic component so I guess that's causing a reaction.
You might have a problem with oil-based varnish because that can turn yellow after a few weeks.
Can you varnish first and then glue? Or maybe dry with a hairdryer to set the glue again?

Michellenman

I'll try both of those ideas, thanks so much!