Glue problem !

[Alan 45]

what could be causing glue not to set ?


I know things like environment,heat,cold,grease,ect can effect these things but these Ive had to rule out as the plastic is always cleaned by myself and we haven't had any hot or cold days for it to be a weather problem


Now here is the strange part , the last two aircraft I have built I've had a problem with the landing gear on the port side and it's the same problem exactly and I've had no problem anywhere else on either model or any model I've built in the last month so what could be happening here?


Why is it localised ie landing gear and why is it the same side ??


Baffled to say the least !

[Ian M]

Silly question I know but is the plastic the same... I have had a couple of kits where the u/c legs have been a tough nylon type plastic. Poly glue will not work. CA does.


Have you tested the glue on some thing else? I've never heard of poly glue going off though.


Ian M

[Guest]

No that is strange I know ca can go off but not heard of poly doing that, and anyway you've said it worked elsewhere on the model. As Ian says maybe it's a different type of plastic. Poly works by melting the plastic together maybe one of the parts is the wrong type of plastic for the poly.

[Alan 45]

Silly question I know but is the plastic the same... I have had a couple of kits where the u/c legs have been a tough nylon type plastic. Poly glue will not work. CA does.
Have you tested the glue on some thing else? I've never heard of poly glue going off though.


Ian M

It's quite a reasonable question Ian and I'm afraid it's no the plastics are different , ones a hobby boss kit the other is airfix the only thing that is the same is the glue which is the humbrol needle type so I can only think it's an external factor causing it , I think in future I'll just use CA for undercarriage or build it in flight


I've built a few other kits in between these two without any problems and they've been different plastics as well


I have now sorted the problem but it's a strange one I'll say that

[takeslousyphotos]

I think you may not be alone in this Alan ...........


[ATTACH]106359.IPB[/ATTACH]

[eddiesolo]

At first I was going to say old glue, oxidised so is not bonding as well. But if it is okay elsewhere and is only in one place then it has to be the plastic-not clean enough-or even some release agent has got into the plastic itself so is making it not bond properly. Try sanding the affected edges lightly to form more of a key, this may help or use CA on these trouble spots-deffo baffling though.


Si

[Alan 45]

It could have been missed si when I washed them but only two parts on two different aircraft weeks apart on the same side ???


Strange that , I wonder if the discovery channel would make a programme out of it

[eddiesolo]

I wonder if the discovery channel would make a programme out of it

I think at least a 3 parter would be needed on this problem Al

[Alan 45]

I think at least a 3 parter would be needed on this problem Al

Only three I think this could spark conspiracy theories


The luminarty made my planes fall over !

[eddiesolo]

The luminarty made my planes fall over !

Only the luminarty!? Could have been mystic forces or even aliens!

[Alan 45]

Only the luminarty!? Could have been mystic forces or even aliens!

See even you can see it

[Snowman]

That reminds me of my days in the airforce, refueling Canberra's..... Front tank- Wing tanks - Rear tank (if I remember correctly) or else you will have to explain to the fitters why their kite is sitting on its @rse with its nose in the air...o_O

[zuludog]

When you weld two pieces of steel together, you use intense heat to melt the metal immediately next to the joint. The molten metal from each piece flows into the other; or intermingles; or mixes, or however else you want to describe it. Sometimes extra metal is added in the form of a welding rod for additional strength or to help fill the gap.


Gluing two pieces of polystyrene together is a similar process, except that the plastic immediately next to the joint is turned to liquid by a solvent which dissolves the plastic. When the solvent evaporates you're left with the two pieces joined together


The long established type of glue is polystyrene cement, which is a solvent containing dissolved clear polystyrene to make a thicker liquid or gel and so make it a bit easier to handle, and slow down the evaporation rate. As the solvent evaporates, so the glue dries/sets


Liquid glue is simply the neat solvent, without anything added


Thus the drying or setting rate of polystyrene cement or liquid glue depends on the evaporation rate of the solvent


Even if the glue does not attack or dissolve a particular type of plastic because it is resistant to the solvent, the glue itself should still dry or set; ie the glue or cement should dry even if it sits on the surface, and the component is not fused into it


As far as I know, there are only two reasons why liquid glue or polystyrene cement will not dry


There is some sort of cover or container over it, so that the immediate atmosphere above the glue is saturated with solvent, thus preventing any more of the solvent from evaporating. This is, of course why glue will stay liquid in a tube or bottle.


The temperature is so low that the solvent will not evaporate; the lower the temperature the slower the rate of evaporation, till eventually it stops.


I once lived in a bedsit which was very cold in the winter and it took days for the glue to set properly.


You probably know this already, but it doesn't really explain why some parts of a model take longer to dry, unless you put too much glue on in the first place


Your post doesn't say if the glue does dry eventually

[Guest]

Well I think it's a time shift phenomenon. You glue the parts together then those pesky Russians turn the time ray on your wings and hey presto you've not put the glue on yet, or maybe it's the Chinese, they have one too, oh no wait it's the Korean's. Sorry got to run here come the men in the white coats.

[Alan 45]

When you weld two pieces of steel together, you use intense heat to melt the metal immediately next to the joint. The molten metal from each piece flows into the other; or intermingles; or mixes, or however else you want to describe it. Sometimes extra metal is added in the form of a welding rod for additional strength or to help fill the gap.
Gluing two pieces of polystyrene together is a similar process, except that the plastic immediately next to the joint is turned to liquid by a solvent which dissolves the plastic. When the solvent evaporates you're left with the two pieces joined together


The long established type of glue is polystyrene cement, which is a solvent containing dissolved clear polystyrene to make a thicker liquid or gel and so make it a bit easier to handle, and slow down the evaporation rate. As the solvent evaporates, so the glue dries/sets


Liquid glue is simply the neat solvent, without anything added


Thus the drying or setting rate of polystyrene cement or liquid glue depends on the evaporation rate of the solvent


Even if the glue does not attack or dissolve a particular type of plastic because it is resistant to the solvent, the glue itself should still dry or set; ie the glue or cement should dry even if it sits on the surface, and the component is not fused into it


As far as I know, there are only two reasons why liquid glue or polystyrene cement will not dry


There is some sort of cover or container over it, so that the immediate atmosphere above the glue is saturated with solvent, thus preventing any more of the solvent from evaporating. This is, of course why glue will stay liquid in a tube or bottle.


The temperature is so low that the solvent will not evaporate; the lower the temperature the slower the rate of evaporation, till eventually it stops.


I once lived in a bedsit which was very cold in the winter and it took days for the glue to set properly.


You probably know this already, but it doesn't really explain why some parts of a model take longer to dry, unless you put too much glue on in the first place


Your post doesn't say if the glue does dry eventually

Cheers Zulu , I did leave it overnight as I do with undercarriage one side set the other didn't ,

Well I think it's a time shift phenomenon. You glue the parts together then those pesky Russians turn the time ray on your wings and hey presto you've not put the glue on yet, or maybe it's the Chinese, they have one too, oh no wait it's the Korean's. Sorry got to run here come the men in the white coats.

Ken the Russians and Koreans !, how absurd! It's obviously the umpa lumpa God inostickayourglue