crack in plastic

[GreyFox132]

alright so there is a crack going down part of my famas. I was wondering what sort of adhesive should i use to secure this so that it doesn't get any worse?

[Drache]

A bible to pray that it doesn't get worse? I have of people using things like JB Weld but I wouldn't suggest it really.

[GreyFox132]

damnnn so there is no real solution?

[Syn]

take a pic. Depends on where the crack is. You could try to brace the crack from inside with a strip of thin plastic and glue to reinforce it and so the crack does not get worse.

jb weld? hmm the package says it sticks some plastics so a 50/50 chance. I would try to glue from inside because glue on the outside is hard to sand down (esp jb weld) and also looks like shit, unless you spray paint it which is a whole other can of worms because you have to get the colour right or paint the whole part that has the crack.

edit:if the crack is tight and does not show I would just brace and glue from inside (if possible) and leave it.

edit2: anyone out there try ABS glue (for pipes) to fix a similar problem. I know abs and pvc glue are pretry strong because I used it at work and home.

[Drache]

There are many products like Weld-On which is made to glue ABS plastics but I've never personally used any on an airsoft gun. The problems with FAMAS' is that there are no spare parts like body kits made for them that I can find.

Unless someone offers a better solution go down to your local hardware store and ask for an ABS Glue. Sand the area of the crack to get rid of the finish over the crack, apply the glue and let dry the maximum amount of time it says for that glue. It won't look pretty and I'll probably get flamed for this but that is the only thing I can think of until someone posts a better way.

[GreyFox132]

sorry bout the blurry pic, all i have is a web cam atm but you can see the crack and the mech box is just behind it
luckily the mech box cover helps support the crack so that it does not move as much, and it also hides it so if its kind of ugly it will still do

[Drache]

Yeah I would use an ABS plastic on the inside of the gun like I suggested above. ABS is a very hard material to glue so thus using an glue made for ABS would be allot better than JB Weld. You will need to make sure to sand the area well though or the glue might not stick to the finish in the ABS.

The only thing I like about JB weld is that you can sand it and paint it unlike most glues. I used JB Weld on many parts of my '69 Skylark but those were 90% metal then sanded and painted.

[GreyFox132]

okay well i have some proweld which my dad uses for building model trains, and i have some insta set. The proweld says its meant for abs and acrylic, and the insta set makes it set faster. Any one see any problems with this set up?

[Kokanee]

Go down to your local hobby store (or ask your dad, if he builds model trains he will know what this is) and ask for some plasticard. It's plastic in sheet form of various thickness. Glue that onto the backside of the crack if there is enough clearance, then let it cure before you start working on the front.

[markedman]

A drop of MEK (Methyl Ethyl Ketone) will bleed down the crack, Melt the plastic fuse it back together and then flash off all in about five minute. It's kinda like paint thinner or liquid model glue but a lot more aggressive. what ever you do avoid using the model glue that comes in thoses stupid little tubes. They don't bite into the plastic enough to be useful
Also if you go to UNcompany.com and search Famas you will get about 30 hits for spare body parts, Naturally not the piece you need but all the rest can be had

[Nik12]

If you've glued it and gamed it and find that for some reason the crack is still getting bigger be sure to drill a hole at the very end of the crack (doesn't have to be a big one). Ofcourse, you might not have to do this if the glue keeps it together just fine, but it's something to be aware of just in case.

[Flying Squirrel]

Originally Posted by markedman

A drop of MEK (Methyl Ethyl Ketone) will bleed down the crack, Melt the plastic fuse it back together and then flash off all in about five minute. It's kinda like paint thinner or liquid model glue but a lot more aggressive.

Actually, There is a model railroad glue called "Tenax" its essentially the same thing (its got MEK in it as one of the ingredients). Its a plastic welder. I have used it on my M3 Benelli and my P90. . . . as well as a ton of other stuff on my train set. It has not failed me yet and I've fielded both guns fairly heavily since the repairs.

If the crack reappears and or continues to grow; try drilling a relief hole at the base of the crack (where it is going, not where it started) and then re-glue the crack, and plug the hole with epoxy. . . Thats an extreme measure though.

[GreyFox132]

i glued the crack with the plastic adhesive i mentioned and it seems to have helped a fair bit. I also tightened all the screws so that it keeps the gun very stiff. When i try to bend the gun nothing opens up so it should be okay

if it comes to the point that i need plastic card i will have to figure out a way to remove the mech box properly.

also uncompany does have the part ineed which gives me a bit of extra help if the crack worsens :P