Flashing on 4" Skirted Chub Grub -

[sim]

Hey -

Got my new mold over christmas - I'm seeing some flashing on the tails of the grub - seems to start at the "ridge" only - its not apparent on the inside of the grub tail - only on the ridge and around to the tips - and its enough that both tips "join' with the flashing.

I've tried adjusting where i'm clamping as well as the amount of pressue (injecting and clamp) - to no avail.

Its not bad - but its definitely present - 

any ideas?

[Denny Welch]

This may be a longshot, but try injecting at a lower temperature.

[MonteSS]

I use a vice and clamp hard at the twin tails. Kind of a fine line on temp and pressure on any mold with a spline. You want the spline to fill out but obviously not get flash.

[andrewlamberson]

I would also add ...inject slower.

Clamp well
Shoot at the lowest temperature that fills out the bait
Inject with less pressure/ slower speed

Andy

[sim]

Thanks for the tips so far - I feel like I've been injecting slow - but i've only messed with it twice now (just enough to get a couple of samples made to see the bait, its cold in the garage).... Just wanted to be sure it was me and not something else.

I've been placing it in the vice - I'll try using clamps instead as well.

I don't have flashing issues with any of my other molds - this one is a little 'longer' than most due to the spline - so might not be getting even pressure withthe vice - just found it strange that the _only_ flashing was around the 'ridge' on the tails.

Temp range was around 310-320 (remelts, not fresh)

[Jerry V]

I believe if you start with consistent and firm clamping combined with moderate pressure and a short "pressure pause"  (10 sec. or so) at the end... you will likely find a nice looking bait.  The pause is to help shrinkage dents as that is a pretty big bodied mold.  A hot mold helps you there too.

Flashing usually equals, uneven clamping, something stuck on the mold face, plastic too hot, too much pressure or something like that.  If you continue to have trouble with it, give me a call or shoot me a PM and I'll see what I can do to make it all work out.

Jerry

[sim]

The wierd part on the flashing is that it is even - its a perfect bit of flash on the outside edge - evenly spaced all the way around the outside edge starting @ the 'rib' - I don't think I can get a camera to pick it up.

I Plan to play some more with it tomorrow - if I don't get it figured out, I'll send you a PM and maybe a bait or three.

[sim]

Minor update - messed around a little this afternoon - heated evertyhing up in the oven, then did some simple injections -

Using 2 clamps - I still got flashing - placed at 'each end' as far in as the clamps would allow and clamped tight. These are not the 'really good' clamps but the Harbor Frieght version, so may have been a factor.

Went back to the bench vice (4" jaw) - off centered so the jaw was firmly over the tail portion of the mold - clamped tight - no flashing to speak of on the tails - of course, the skirt side had some flashing now.

So - I either need to find a way to adapt the vice to a larger jaw or possibly try the Irwin clamps that I have put off getting since I use the bench vice primarily these days.

Still getting quite  a bit of dented body - but I'll just have to count to 20 (difficult when I have shoes on).

[Bugpac]

If your vice will open far enough. Add a 2x4 on each side to support the length. All I use is a vice generally.

[andrewlamberson]

It would seem that if you are getting both flash and dents you are shooting too hot. What temperature are you shooting at? Try going down to 330 or even 320 and see if that helps.

Keep going lower until the flash goes away...but the tails still fill.

Andy

[sim]

It would seem that if you are getting both flash and dents you are shooting too hot. What temperature are you shooting at? Try going down to 330 or even 320 and see if that helps.

Keep going lower until the flash goes away...but the tails still fill.

Andy

I was around 320 this afternoon - I'll try going 'lower' yet on the next tests - going to do some twinjector stuff and see how they come out.

[sim]

If your vice will open far enough. Add a 2x4 on each side to support the length. All I use is a vice generally.

I'd thought about that, plus it 'protects' the molds from overtightening to a degree - just trying to think of a way to 'mount' the 2x4s so its not so clumsy getting things together.

[ctom]

Sim, if you can handle the two lengths of two X four in your vise, screw a 1X6 cut to the same length across the top. When the vise is opened enough for the mold to get put in or taken out your blocks will just tip in and not be falling out. I have a bunch of these made up to hold wood while I work on it clamped in the bench vise so the wood won't get marred.

[sim]

I picked up a 'woodworkers' vice from Lowes - fits the mold better but doesn't quite have the 'clamping' power - but its more even in its clamping so I get less flash.

Going to try and find some 1/4" neoprene/gasket type material to see if that will firm it up a bit more.

Nice thing about this one is that its at table height (flush with the top of the bench) - so if I can get just a little more 'pressure' with it, it should make things even smoother.