plastic welding help, please?
 

ok, i need help doing this whole solvent welding deal...

first off, this is what i am using welding solvent on:

http://i272.photobucket.com/albums/j...r/IMG_0128.jpg

http://i272.photobucket.com/albums/j...r/IMG_0129.jpg

and this is PLastruct 0.040 styrene:
http://i272.photobucket.com/albums/j...r/IMG_0130.jpg

and i am trying to weld it as the back wall of a truck cab, like so:
http://i272.photobucket.com/albums/j...r/IMG_0133.jpg

and this is the solvent i am using:
http://i272.photobucket.com/albums/j...r/IMG_0132.jpg

i am following the instructions on the bottle and the styrene to the letter, but i am having prolems maing the two stick.

my major questions are:
1.) is it because i am trying to bond too thick of an area?

2.)or is it because i am trying to bond 2 different types of plastics?

3.) is it possible to use too much solvent and not be able to make it stick?

4.) on perpendicular bonds, where do i apply the solvent? on bothsides of the joint? down the skinny part of joint?

any help would be greatly appreciated...

First I'll assume that the body is polystyrene . The plastruct solvent is not that strong IMO . Ambroid PRO WELD is better , bonds styrene , butyrate , abs , and acrylic . I use an old drafting dip style pen , has an adjustable tip , to apply the solvent to the joint . Let the solvent run in the joint , and keep your fingers clear or you'll be sanding out your prints . Let the solvent melt the plastic then you can wiggle the joint to help tighten the joint , or make a weld "look" . I've also had luck with acetone , and Tenax-7r . You just may not be applying enough of the solvent you have to dissolve the plastics in the joint .
The wetter you make the joint , the longer it will take to dry .

Try a small area inside the body to see if that solvent melt , or softens it . some abs plastics wont react , you might need to try welding with a soldering iron (with a piece of plastic that matches the body ) .

A couple possibilities.

I haven't played with one of those bodies, but if it's anything like the 1/6 Ranger, it's made of the oiliest fawkin plastic ever invented; good luck getting anything to stick to it with a solvent-based glue. If it feels dry to the touch, and doesn't leave a wet fingerprint every time you touch it, then you're probably ok.

See if you can find some Tenax-7R. It's more potent than the Plastruct stuff and a little more forgiving of dissimilar plastics.

In answer to 3, yes. A little is good, more is better, too much is a fawkin mess.

Hit the joints with solvent anywhere the two parts touch.

tenax will glue to that body.

it has a stiff rubbery feel to it, if that helps


not to sound dumb, but is this before or after using the solvent on that plastic???:shock:

also, where do you pick up tennax at? LHS? auto parts store? ACE hardware?

also, thanks for the input guys. it has been a big help!!!;-)

Best quote ever :flipoff:

Sounds like it's made of what I call Chirene: Chinese styrene, not easy to glue. Some of it's so oily that you leave a fingerprint on it even if your hands are clean.

Your best shot would be the Tenax. If that won't do it, use CA backed with Shoe Goo.

Your LHS should be able to order Tenax for you if they don't stock it.

haha, i was thinking the same thing about this::lol::lol:

thanks for the help. there is a hobby shop close to me that specializes in mostly trains. they sound like that should be a good place to go.

there is always good ol' 2 ton epoxy or gorilla glue. They pretty much bond anything.