Dumb proseal question

[tshort]

Just wanna confirm...
10:1 means 10 parts of one and one part of the other (total 11 parts), not 9 of one and 1 of the other (total 10 parts), right ?

Also, how much "resolution" do I need if I get a digital scale?

T.

[TomNativeNewYorker]

10 to 1 would be correct.

Example 100 grams part 1 and 10 grams of part 2.

[prestwich]

Also, how much "resolution" do I need if I get a digital scale?

T.

I'd say one significant digit past the quantities with which you're working. To mix up 1.1 pounds of goo, I'd get a scale that resolves to 1/100 pound. (Since you'll be using 1/10 pound of catalyst.)

[Wicked Stick]

I used/use a small digital scale that are designed for measuring ingredients for cooking/baking.

I measured my pro-seal in "Grams" About 30 or 40 grams a shot.
40 grams of the white stuff, and 4 grams of the black stuff.

Note the white smells like rotten eggs when opened, but after mixing it, the smell subsides quite a bit.

There's room for a small amount of error on the mix. If your slightly weak on the black stuff, it will take longer to fully cure. If you mix slightly stronger on the amount of black, then it will setup faster.

[tshort]

Any suggestions on where to get a scale that measures to 0.1g?
If I'm gonna measure 40/4 I guess that would be a good amount. most of the ones I see online are 1.0g units...

I'm thinking about just making a balance beam...

T.

[captain_john]

Thomas, I made the balance beam but couldn't get it to work consistently and I dunno why...

Use a food grade scale from a chef suppy store and you will be fine. The digital one like WS mentioned is really quite accurate.

10% tolerance is probably the max you would want and the scale will provide much better than that.

Combining the ingredients "oxidizes" the white stuff, the black stuff being the oxidizing agent. If you are strong, it cooks quickly. If weak, slowly.

So long as it is THOROUGHLY MIXED, the results will be fine either way.

CJ

[LooseNut]

I've been thinking (could be dangerous) ...

When I measure the pro-seal on the kitchen scale real careful-like ... especially when I'm mixing up a small blob ... say 10g ... it doesn't come out real consistant.

How do I know the mix is bad? First the color is off (too light or too dark), and then the stuff sets up much slower than usual, or much faster than usual.

If I mixed up a big batch ... say 1 lb ... the measurement errors would be negligable, and the mix would work out great ... but, suppose I want a little blob ...

Why not use color instead of weight to fine-tune the mix ratio? My eye is not very good at judging an absolute color, but, I can compare two samples and see the difference pretty easily. So, if I compare a new batch that I'm mixing to a sample of properly mixed pro-seal I can duplicate the shade of gray pretty well. I think this works 'cause the color of the pro-seal doesn't seem to change much as it sets.

Here's the best part ... all those smears and blobs of pro-seal all over the work bench ... well, they aren't a mess ... now they are my mixing guage!

So, here's how I mix up a small blob of pro-seal ... I use the scale and put about 10g white and about 1g (maybe a little less) black ... I mix it up real good ... then I hold it up to one of my reference smears on the bench (or a finished seam someplace) ... if it doesn't look right, I add a bit more of white or black (usually black).

This seems to work for me. Dispite my wordy explanation, it's actually faster and easier this way than trying to get super-acurate weights on the scale. And, I think I'm mixing the stuff much more consistanly now.

What do y'all think? Are my tanks gonna fall apart?

LooseNut

[jim_geo]

Try a sporting goods store or shooters supply. Powder scales aren't expensive and they are accurate.

[tshort]

I got a cheap scale at target yesterday ... got some funny looks, too as I bought a bunch of ziplock bags along with the scale. Good thing there wasn't a cop around or he may have followed me out !

Thomas

[captain_john]

Harold, your tanks are gonna be fine. If you are that close, all that will be variable is setup time.

So it takes 3 days to fully cure, so what! On the other hand it may take 6 hours, okay... so be it.

The black stuff is an oxidizer. The white stuff will harden without it. It just takes much longer. The black stuff just speeds the process.

Mix it THOROUGHLY. That is the key.

CJ