Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Glue etc. => Topic started by: Charlie on September 21, 2020, 09:32:22 am

Title: Plastic Weld vs Acetone
Post by: Charlie on September 21, 2020, 09:32:22 am
I've always used Plastic Weld for gluing styrene joints, but as i had a bottle of Acetone i thought i would try this. It seems to work pretty well. So is Plastic Weld actually just Acetone? Or is there any downside to using Acetone?
Title: Re: Plastic Weld vs Acetone
Post by: JimG on September 21, 2020, 11:55:44 am
Plastic Weld contains Dichloromethane (Methylene chloride) a harmful solvent which is why you should use it with good ventilation. Acetone is another solvent although less harmful but still should be used with good ventilation. Acetone will evaporate more quickly and is probably more flammable due to this, the vapour will spread out quickly so you mustn't have any source of ignition nearby. The faster evaporation may lead to the join being weaker as the plastic in the join will not dissolve so much and give a poorer weld.
Jim
Title: Re: Plastic Weld vs Acetone
Post by: Charlie on September 21, 2020, 02:01:42 pm
Thanks Jim, good to know
Title: Re: Plastic Weld vs Acetone
Post by: CGAux26 on September 21, 2020, 02:55:42 pm
I use MEK to make joints in styrene.  First learned of it in the instructions for the Model Slipways Loyal tender. 


Put a small quantity in a glass jar with a tight lid, like a baby food jar.  cut up some styrene scraps very small and add it to the jar.  It dissolves in 24 hours or less, and acts as a filler in joints you make.  Use a small artist brush to apply it to joints.


Same safety precautions as mentioned in the other entries above.
Title: Re: Plastic Weld vs Acetone
Post by: ballastanksian on September 21, 2020, 04:01:31 pm
Well, you learn something new every day! I did not know you could use Acetone on styrene. I knew of it being used in the forties/fifties for sticking together cellulose based kits as described by an old modeller friend, but not that it had a similar effect on styrene plastics.


I learnt that during 'Ketosis' where the body breaks down fats, the body makes acetone and it can cause kidney failure.
Title: Re: Plastic Weld vs Acetone
Post by: Charlie on September 21, 2020, 06:07:18 pm
So i just had a quick look on eBay, and a 50ml bottle of Slaters MEK Adhesive is £10.85. Or you can buy a 1 Litre bottle of 99.9% Pure MEK for £10.95! I can't believe I have only just found this out; i could have potentially saved a small fortune over the years!
Title: Re: Plastic Weld vs Acetone
Post by: mudway on September 22, 2020, 10:44:37 am
I use MEK to make joints in styrene.  First learned of it in the instructions for the Model Slipways Loyal tender. 


Put a small quantity in a glass jar with a tight lid, like a baby food jar.  cut up some styrene scraps very small and add it to the jar.  It dissolves in 24 hours or less, and acts as a filler in joints you make.  Use a small artist brush to apply it to joints.


Same safety precautions as mentioned in the other entries above.


Do you clean the brush with MEK?
Title: Re: Plastic Weld vs Acetone
Post by: Big Ada on September 22, 2020, 04:32:12 pm

Do you clean the brush with MEK?

I let the brush go hard, then when I want to use it again, all I do is put it in the MEK for a short time and its ready to go again.
Title: Re: Plastic Weld vs Acetone
Post by: Big Ada on September 22, 2020, 04:36:24 pm
Another Tip, from a Plumber ( = me Retired ) go to a Plumbers Merchants and ask for Plastic Pipe Cleaner NOT the Glue, that is used to join Bath and Basin Waste Pipes, I have used it for years to weld Styrene.

Len.
Title: Re: Plastic Weld vs Acetone
Post by: CGAux26 on September 22, 2020, 07:35:30 pm
I just wipe my small brush dedicated to MEK very dry after use.  It does not get too hard and as soon as it goes into the jar again it is soft and ready to go.


BTW a quart of MEK at local home stores is about $9.00.  That's pretty much lifetime supply.