[user1127]

Hello All -
I've search back for 11 months and read veterans' thoughts and preferences on Teanx 7, Amroid Pro-Weld, Testor's Liquid cement, Home Depot MEK, etc.
My final glue question is: will putty products (Testors Red) ingredients hinder or degrade the 'welding' properties of liquid cement?
Yes, I know (or at least have read) Tenax 7 and Abroid PW are essentailly the same, but I've had no luck with Tenax after it dries when I use putty or primer on seams.
-thanks.

 

[jwrjr]

I prefer ProWeld and I have not had that problem.

 

[user1127]

Thanks, Light Savior :^)

 

[Darth Bill]

Your basic spot putties contain a solvent that will attack styrene. Given that you're applying it to seams, it may be getting in and affecting a weak glue joint. Most likely the problem is with the bond made with the Tenax. . . but it's not the fault of Tenax-7.

Tenax-7 is very volitile and evaporates when you look at it. Often the styrene already set up before you get parts together, which will cause weak joints.

I've moved to ProWeld because it gives a little more time to get the bond right, but still acts as a fast setting solvent.

 

[Nova Designs]

I agree. In addition I tend to use water-based putty like MagicSculpt since it will not interfere with the glue, won't shrink as it dries and will not attack the plastic. It also takes a while to set up so you can work with it a little longer and easily clean up excees that might interfere with details like scribed lines etc...

 

[Brent Gair]

Tenax-7 is very volitile and evaporates when you look at it. Often the styrene already set up before you get parts together, which will cause weak joints.

Tenax should only be used by applying it to parts that are already being held together. There's no way you can possibly make an acceptable joint by applying to a surface and then closing the joint.

I use it on all my fuselage joints (wings are a bit different). But I hold the fuselage together between my fingertips and apply the Tenax with a brush, allowing capllary action to draw it into the joint. That's really the only way to use it.

The various lacquer based putties have no long term ill effect on glue joints. But, just like glues, they have solvents which makes them bond to the plastic. That's why I like them. I actually prefer plain red Bondo Spot and Glazing putty. During that brief period before the putty dries, it could theoretically affect a joint because, after all, you are adding a solvent to the specific are. However, just like glue, once it dries everything will be just fine.