Using Weld-on 16 Whats with the air bubbles?

[BOKER420]

I'm using Weld-on 16 in a tube to glue the seem from my skimmer flange to the funnel I made. After it sets for a few minutes it starts to sho air bubbles in the glued seem.

How do I apply this so I don't trap any air?
thanks,
Bill

 

[a4twenty]

IME weld on 16 always leaves air bubbles. it has to do with the amount it shrinks when drying. i use weld on 4 for butt joints, then reinforce the joint with a fillet of weld on 16. it may not look that great, but it is strong and water tight.

 

[jman77]

I have clean seams with Weldon 16.... did you clean the ends b4 you put the weldon on there ?

Weld on 4 is alot easier to work with for having cleam seems though. Weld on4 and the pin method works nicely

 

[BOKER420]

The seam was tricky since it was a circle for starters and then at an angle. I used Weld-on 4 to start out with but I didn't have the pieces perfectly matches up so there was a bit of a gap in one spot so I went over it with a bead of Weld-on 16. Like Twenty said it doesn't look the greatest but I think I finally got a good enough seal to be watertight.

I think next time I'll use Weld-on 40 for anything like this.

Thanks for the inputs.

 

[us2000ua]

How do you apply Weld-on 40? What tool?

 

[BOKER420]

You can use a needle applicator just like Weld-on 3 and 4. Just make sure it is the right gauge needle.
I think Ridout Platics suggests a 64 gauge needle for Weld-on 40but I might be off.