Fixing cracked or broken plastic with super glue and ?

[A modeler named mike]

I know I saw somewhere here a topic where someone suggested using super glue and adding either baking soda or powder to create a stronger bond? I've looked and I can not seem to find it again. Anyone?  I have a cracked window pillar that is snapped off at top and bottom. One break is a clean break but the other break has a very small chip missing. Thanks in advance..

[stitchdup]

you can use pretty much any powder with superglue. I personally wouldn't use baking powder as i've found if there is any moisture it froths up, sometimes months later. Just gather up some plastic dust and use that instead. or fingernail filler powder works too if you want a solid piece but it works better when used with its own catalyst. it basically a kit for making acrylic nails but it works fine for our hobby too, though it is very stinky so a good mask is required with it. kits are available from the big warehouse store for not much $s, mine was about $7 delivered

[NOBLNG]

Apparently baking soda is not a good idea.

 

[Pat Minarick]

I will never use baking soda again. I know it will start an argument,  but if you live anywhere that is damp or humid alot you will be sorry. You can use Micro-balloons , it's a filler for remote control airplanes with epoxy or superglue. Haven't had any problems with it and works about the same.

[A modeler named mike]

36 minutes ago, stitchdup said:

you can use pretty much any powder with superglue. I personally wouldn't use baking powder as i've found if there is any moisture it froths up, sometimes months later. Just gather up some plastic dust and use that instead. or fingernail filler powder works too if you want a solid piece but it works better when used with its own catalyst. it basically a kit for making acrylic nails but it works fine for our hobby too, though it is very stinky so a good mask is required with it. kits are available from the big warehouse store for not much $s, mine was about $7 delivered

Thanks Les for the info. I think I'll stick to your styrene dust method. Since its an older kit I'm guessing it best use the plastic filings from that kits leftover trees. Not sure if it even matters but I'll play it safe.  

Thanks Greg for the warning.. It's best to learn from one's own mistakes but I never turn an ear away to listen to someone else's.

[peteski]

1 hour ago, Pat Minarick said:

I will never use baking soda again. I know it will start an argument,  but if you live anywhere that is damp or humid alot you will be sorry. You can use Micro-balloons , it's a filler for remote control airplanes with epoxy or superglue. Haven't had any problems with it and works about the same.

No arguments here. Baking soda and CA  always was and still is a bad idea, especially since many filler alternatives exist, are easily obtained, and inexpensive.   And for quick hardening there are multiple brands of CA accelerators. Person who thought that idea up should be banned from giving modeling advice forever.

[Straightliner59]

Although, good ol' sodium bicarbonate still makes a pretty decent antacid!

[Bainford]

23 hours ago, A modeler named mike said:

I know I saw somewhere here a topic where someone suggested using super glue and adding either baking soda or powder to create a stronger bond? I've looked and I can not seem to find it again. Anyone?  I have a cracked window pillar that is snapped off at top and bottom. One break is a clean break but the other break has a very small chip missing. Thanks in advance..

It is my understanding that adding a powder substrate to CA glue does not make it stronger, and may make it less strong. Adding a powder to CA is used when needing a filler. For maximum bond strength, use the CA straight, and without accelerator. Further strength can be achieved by bonding a length of 1/32" brass rod on the back side of the a pillar.

[bobthehobbyguy]

You are definitely going to need to add reinforcement to the windshield post. Superglue does not have a lot of shear strength.

[A modeler named mike]

4 hours ago, Bainford said:

It is my understanding that adding a powder substrate to CA glue does not make it stronger, and may make it less strong. Adding a powder to CA is used when needing a filler. For maximum bond strength, use the CA straight, and without accelerator. Further strength can be achieved by bonding a length of 1/32" brass rod on the back side of the a pillar.

Question?? With the rod support glued in place, does where the windshield meets that pillar need to be scribed or channeled out for a snug fit? I'm all ears.. 

[stitchdup]

It probably will but you can also put the channel in the frame itself. it would make the repair stronger. You might still need to do a channel in the glass too depending what you use for the support and how much plastic there is on the frame. A flattened staple from a magazine might be good option for something thin

[A modeler named mike]

34 minutes ago, stitchdup said:

It probably will but you can also put the channel in the frame itself. it would make the repair stronger. You might still need to do a channel in the glass too depending what you use for the support and how much plastic there is on the frame. A flattened staple from a magazine might be good option for something thin

After going back to look at exactly what I've got to work with it appears that a rod would workout better in this situation. I attach 2 photos.. Not happy that I found both pillars had been broken once..? that could be under the what irked me today topic.. Anyway the pillars have a concave channel that runs the length of them making the rod a perfect choice. Time to order some rod or take a look at my electrical wire remnants.

[Bainford]

Yup, a little metal support will work well there. As you suggest, some small mod of the glass may be required to accommodate the support rod. As Les mentioned, there are many materials that can be used, and thinner materials will help with the glass install. I mention 1/32" brass rod only because I have a bunch around and use it for a gazillion things. A thin strip of pop can aluminum may work as well, though sand the thin plastic coating from the can before cutting and gluing. Many other things can be used, too.