Epoxy primer (Interprotect) mixin ratio by weight?

[VicS]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

What? Where did you see these? It's not listed in the datasheet, from what I can see?

As I said in #2 Safety data sheets, Chemical and physical properties

part A: http://www.yachtpaint.com/gbr/diy/products/pages/MSDS.aspx?PDF=IA|329608 ..... section 9 ...... relative density 1.58

part B: http://www.yachtpaint.com/gbr/diy/products/pages/MSDS.aspx?PDF=IA|329551 ..... section 9...... relative density 0.88

1.58 x 3 / 0.88 = 5.39

 

[GHA]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

1.58 x 3 / 0.88 = 5.39

Theory matches closely with experiment - isn't science wonderful and interesting and fun!

 

[Lomax]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

Theory matches closely with experiment - isn't science wonderful and interesting and fun!

Best. Post. Ever. :encouragement:

 

[Lomax]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

As I said in #2 Safety data sheets, Chemical and physical properties

My apologies, that failed to register. A lot going on here. Still, the experimental evidence, and the fact that it matches well with what's said in the MSDS, is certainly worth something.

Edit: I still think International ought to include this information in the datasheet proper, considering how common the practice of mixing epoxy by weight is. Outside this forum anyway.

Edit 2: Epifanes know how it should be done (as usual):



I wish my local chandlery would carry their paints instead of International's. Have to wait a week(!) to get anything from Epifanes.

Edit 3: I've solved the mystery of the missing asterisk; I was using Qalculate! to run the numbers, and copy-pasted from it - it turns out that the default multiplication sign used by Qalculate! is a Unicode "dot operator" sign, though in the preferences you can change this to "×" or "*".

 

[Lomax]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

And here's how you mix 2-pack paint like a pro:

First tare the scales with an empty container. Then place the equivalent desired weight of finished paint on the scales, and set this as 100%. I use water, but bear in mind it has lower density than the paint; you'll end up with somewhat less paint than water (volume wise), but to me that's actually a good thing, since I always overestimate how much paint I need! Add "part A" to a clean cup until you reach the required percentage - 81.5% in this case:



Now add "part B" until you reach 100%:



And that's it.

 

[coopec]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

Lomax

Well I've got a simpler way!

My wife knows to never throw out any washing machine soap powder scoups because she knows I need them as measures for my epoxy.

Clive

 

[Lomax]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

soap powder scoups

How do you compensate for the fact that the "part A" component is incredibly sticky and viscous, while "part B" runs like water? If you don't, you'll end up with way too much of "part B". How do you measure "part B" - or do you always mix a multiple of four "powder scoups"? Since I'm only doing patch repairs that would be too much for me. Do you use a separate scoop for each part? You should, or you will ruin your stock. How many boxes of soap powder do you go through in a week? I currently mix Interprotect every other day or so, which would require something like 6-8 plastic scoops per week. What if you needed to mix a larger quantity, say a pint or so, doesn't it get awfully tedious with all that scooping? Ever lost count?

IMO there exists precisely one method of mixing this paint that is easier and quicker than the "by weight" method - and that is to dump the entire contents of an unused "part B" container into an unused "part A" container. Provided of course that International supply them in the correct ratios...

 

[coopec]

Re: Epoxy primer (Interprotect) mixing ratio by weight?

How do you compensate for the fact that the "part A" component is incredibly sticky and viscous, while "part B" runs like water?

I have a very small putty knife to scrape the measure to ensure the measure container is empty.

What if you needed to mix a larger quantity, say a pint or so, doesn't it get awfully tedious with all that scooping?

As stated in a previous post I bought a lot of different sized plastic measuring flasks very cheaply off eBay so I select the appropriate sized one.

How do you measure "part B" - or do you always mix a multiple of four "powder scoups"?

I normally mix a 4:1 batch by using the appropriate sized measures. I might add I always think "what will I do if I have some epoxy mix left over?" I therefore have another use lined up. (It is too expensive to waste)

Clive