Label casting failure

[pkowal]

Ok here it goes.
I purchased some casting resin and hardener from Barnes.
Averu labels J8159.

I sand the sierra tubes affix the labels.
Place in a mold. [no vacum casting yet]
Mix resin with flakes and then hardener at 1.5%-2%.
Pour resin around the Tube.

The Resin sets well but where the label overleps a sort of crack appears right along it.
And when I turn it basically you can spread the cast apart with your fingernails, as if it was placed there on purpose. This blank has not been turned yet but the crack can be seen clearly.:(( The resin is a bit hazy due to the flipflop flakes in it.

116579

Any Ideas maybe seal the labels with clear acrylic paint.
I am trying a label now without the overlap see if this is the problem.

Regards Pete :doh:

[gawdelpus]

Not done any of this casting stuff as yet :) ,but coming. It may be an adverse reaction to the glue on the label that has occured at the edge of the join, These things are pretty finicky from all I have read on the subject . Some one will have a better idea I am sure that has actyally experienced the label casting process, good luck with it , Cheers ~ John

[dj_pnevans]

Pete you will find it is the label. I am still working on how to do this, I have done about 4 pens that worked out but have done many others that have done the same thing as yours. I have been sent some new type labels to try this week and I let you know how I go.
David

[pkowal]

Ok just turned the label with a gap [no overlap].
No crack but I can definately see the label lifting but only where the two ends meet.
Back to the drawing board.
David please let me know how you go with your labels.

Regards Pete

[dj_pnevans]

Will do Pete as soon as the wife get onto her pc she will print them up for me.
David

[pkowal]

Ok done a Label with a overlap but this time I rubbed some medium C/A over the overlap.
Surprise!!!! Didnt work lifted again..

Oh well atleast the beer is cold in the shed to mourn our failures.

Pete

[MBUMIK]

i read somewhere something abount rubbing uncatalized ( i think i just made that up) resin on the labels before casting, not sure but could be work a try

MIK

[dj_pnevans]

Well had a go today. Just remember it is only to see if the label worked, and yes it did. You can see the over lap. Next time I will put a bit of CA around the tube to stop water getting in. The labels are vinyl from www.decalpaper.com.au (http://www.decalpaper.com.au)
David

[joe greiner]

The resin probably dissolved the glue on the label, and created a weak boundary which allowed the label to lift away.

If you're printing the labels, try using a paper without glue. From an existing label, you might remove the glue with naphtha (lighter fluid) or mineral spirits. In either case, smear some resin on both sides of the label while embedding. Wear disposable gloves for all of these operations.

Cheers,
Joe

[pkowal]

Excellent thanking you, will order some of those decals and will post results.
I will be trying Mik's advice about coating the label with resin without the catalyst.

Regards Pete

[dj_pnevans]

Got sent home early today, so I had a quick play in the shed. I had a waterslide label in a mould from Sunday. With this type of label once you print on it you have to spray it then soak in water before putting it on the tube. The label I used was a bit narrow so there was a gap of about 5 mm. The good news is that the sides didn't lift, so this one works as well.
David

[pkowal]

I got the decals, tried several and no crack or signs of lifting.
But and there is a bloody But, there seems to be some sort of void in the cast it is hard to explain sort of like a air bubble but basically right up against the label in several spots. Sort of like silver puddles. Its like the resin is lifting from the Label.:?

Sorry the pictures are a bit out of focus.
118911

The line that you see up top is not a crack its just from my mould.
118912

Here is my labeling procedure.

1. Print labels. Canon Inkjet. I let labels dry for about 5 Hours.
2. Prepare tubes by light sanding and a wipe over with methylated spirits to remove any grease.
3. Apply label to tubes they sit for about an hour.
4. Place labeled tubes in moulds
5. Mix Clear Casting resin "Barnes" with about 1%-2% Catalyst.
6. Pour into moulds
7. Place Moulds on a vibrating surface to rid of air bubbles.
8.I dont touch them for a good 12hrs.

Is there a dance that I am supposed to be doing or maybe sacrifice a goat or something.:doh:
Maybe am I putting in too much catalyst into the resin would that affect it.

I am trying tonight to coat the tubes with resin that has not been catalised before the main resin gets poured in.

[dj_pnevans]

Where you have the void was that part facing down in the mold or on the top?
David

[pkowal]

No the void as you call it is in numerous spots all around the blank.

And my Moulds are pvc pipes laid vertically.
The funny thing is that when I used labels that ware lifting, I didnt have voids. Go Figure?

Pete

[dj_pnevans]

Pete try and spray the label with spray resin let it dry then cast it. Did you try the labels from Decal Paper (http://www.decalpaper.com.au) ?
David

[NewLondon88]

I agree wiht DJ .. it's a void. The dreaded 'silvery shimmer'.

It is an air pocket that can develop at most any time. I've had some great looking castings
develop these after being finished!

There's a few things that can cause it (at least, that's my understanding .. could be many)
but one of the more common causes (in my limited experience) is that the resin is set,
but not quite cured. If it is still flexible at all, you can 'twist' it while turning, you can warp
it while removing form the mold, you can overheat it while sanding .. anything that will
change the size, shape, dimension or the blank OR THE TUBE can cause this.

When you move one but not the other (tube or blank) then an air space can be created..
and that will give you the shimmer. If you heat up the blank while sanding, it can cause
parts of the blank to expand away from the tube. (shimmer) or if you get a small 'catch'
while turning, it can cause the blank to move while the tube stays put (shimmer) or
if you need to push the blank out of the mold with any force at all, it can cause a
slight separation of the blanks from the tube (again.. shimmer)

My advice in that case would be to pour the blanks and then set them aside for a
few days before turning them.. and gently remove them from the mold. turn with VERY
sharp tools and watch for heat.. wet sand only, and stop when they start to get even
a little bit warm. In fact, you could remove them from the mandrel and put them in some
cold water to col them off.

WATCH OUT for your mandrel and bushings.. they can retain A LOT of heat when
sanding!! Might not hurt to keep a large can or jar of water close to the lathe .. and then
just dunk the whole thing in cold water .. mandrel, bushings and all.


Another thing that can cause the shimmer is air leeching out from the label material
itself. This is why some turners use a sealer coat of some type on the labels. It will
depend on the label material, of course, but some are more apt to trap air than others.
And then the resin gets warm, the air bubbles come out of the paper label and they
expand (shimmer!) Some casters also 'paint' the labels with resin before they pour,
it seeps into the labels and can displace some or all of the air inside the label.

There are so many variables .. temp, humidity, mold materials, horoscope etc. that
it isn't feasible to come up with one cause for this problem.. and that's even before you
get to the variables of the resin and labels themselves.

But don't feel too bad, you're not alone. I know 'professional' casters who have been
doing this for years and years ... and once in a while they still get the shimmer.
The best you can do is make yourself a checklist (yes, write it down and check it off!)
to eliminate all the variables you can.

Warm the resin, warm the molds, degas the resin if possible, seal the labels, vibrate
the mold after pouring, pick out all the bubbles you can ..

.. and then leave the casting alone for a few days.

It will still be there.. I promise.:p

[NewLondon88]

Here is my labeling procedure.

1. Print labels. Canon Inkjet. I let labels dry for about 5 Hours.

I just noticed this part .. 5 hours isn't much. Inkjet inks contain a lot of WATER.
Water will react with most resins and form micro-bubbles.. that will give you ....


... wait for it ......


a shimmer.




8.I dont touch them for a good 12hrs.

that's also not much time. In 12 hours, the resin (depending on the brand) might be
set up .. firm to the touch, but not yet hardened.

Do they still smell like polyester resin? Perhaps still out gassing? That could be a sign
that they're not quite 'done'..

[BoomerangInfo]

Go with Charlie's advice. He's an expert in these things. I've had it happen too.

If I ever get adventurous and rich, there's a company in Brisbane that makes plastic labels that could either be a solution to the paper airtrap problem if it bonds with the resin, or a complete failure if it doesn't :)

Russell.

[pkowal]

Yes I bought the labels from Decal Paper, one thing I guess is that they definately dont lift. LOL
Spray Resin? Where do I get this magical potion?

[NewLondon88]

Go with Charlie's advice. He's an expert in these things.


Thanks, Russell .. we're talking about casting failures .. and I'm the expert? :p

That's it. You're out of my will and off of my Xmas list..

[BoomerangInfo]

Thanks, Russell .. we're talking about casting failures .. and I'm the expert? :p

That's it. You're out of my will and off of my Xmas list..

Err, not quite what I meant, but since you brought it up :D

Still working on it.. - International Association of Penturners (http://www.penturners.org/forum/showthread.php?t=39345&highlight=newlondon88+label)

And that's OK about the will, while 500 gallons of silicon and 150,000 labels would be nice, I've got nowhere to store it all :p

Russell.

[NewLondon88]

And that's OK about the will, while 500 gallons of silicon and 150,000 labels would be nice, I've got nowhere to store it all :p.

LOL .. hey .. beds are overrated. I'll bet they would have fit..

[Dorno]

Which lables have you found best David ? The vinyl or the water lables ?

look forward to hearing from you

Ian

[dj_pnevans]

Pete I get spray resin from Fibreglass Resin Sales | WELCOME TO THE WONDERFUL WORLD OF COMPOSITES! (http://www.fibreglass-resin-sales.com.au/) here in Perth.
Ian I just got some more vinyl labels last week.
David

[Dorno]

Thanks david
Just another sticking point no pun intended. I have notice many members having a problem with the join in the label when casting is there a way to stop the join from showing. I have ordered some vinyl stickerrs as you sugested so i am now looking at solving as many problems as I can before hand.

Thanks for your help
Ian

[dj_pnevans]

Ian you will see most joins the best bet is to have next to or no over lap.
David