Measuring MEKP

[62cruiserinc]

What do you guys use to measure out the MEKP for the resin?

I am placing a big order at US Composites for the materials I need and I am not sure what I will need for the MEKP. They have 1 oz graduated cups (100 for $4) and also a "Measure-Matic" made for MEKP ($7). What should I use?


Also, they have wooden stir sticks (50 for $4) or a plastic "mixing stick" ($1 ea) available. Which is better?

Do I need a corner roller?

There are two grades of fiberglass rollers, are the cheaper ones good enough? I was planning on a 1/2" x 5" roller, is that a good size?

Sorry for all the questions, but I haven't done this before and I am looking for help to avoid wasting money. If there is anything else I should be buying, please let me know.

Thanks
Steve

 

[Woodonglass]

Re: Measuring MEKP

I use 2 oz shot glass for my MEKP. I have a wood shop so I have plenty of Scap wood to make stir sticks. If you have to order some order the wooden ones. Never had a corner roller. 1/2" x 5" is perfect just keep it clean with Acetone @ ALL times. I got the good one.

 

[Trooper82]

Re: Measuring MEKP

I got the 500 pack of sticks, way too many. I like using the measurematic, but there is a bit of guestimation on smaller batches. It goes from 0 to 5 ml. @1% on 250ml of resin that is only 2.5ml of mekp. Not too hard to judge, but if you male a batch of 300, 350, or 400 you have to guess. The bubble roller, i went with the highier priced one, 4" & 6" models. They work very well, but like wood said, keep it clean! That has been my largest learning barrier. There is my 2 cents.

 

[TruckDrivingFool]

Re: Measuring MEKP

+1 on the measurematic

 

[tpenfield]

Re: Measuring MEKP

shot glass type of measuring cup. I usually mix small batches, so I am usually measuring 1/4 oz. etc. of MEKP.

I finally learned not to trash my rollers on the first wet-out. I keep a small bucket of acetone and drop it in after each use.

 

[TruckDrivingFool]

Re: Measuring MEKP

I thought about adding this when I posted earlier and didn't but now that they have been mentioned - when using the USC products shot glass to measure at least watch the way they are marked. After having troubles with under-catalyzing I found it best to use the ml/cc scale VS. the oz scale.

 

[tpenfield]

Re: Measuring MEKP

Yup, that's what I use . . .

 

[Woodonglass]

Re: Measuring MEKP

That's the one!!!!

 

[Yacht Dr.]

Re: Measuring MEKP

I thought about adding this when I posted earlier and didn't but now that they have been mentioned - when using the USC products shot glass to measure at least watch the way they are marked. After having troubles with under-catalyzing I found it best to use the ml/cc scale VS. the oz scale.

This is a Dram cup..not what you want..

You need the 7 dollar Bottle that you Squeeze your MEKP into the top vial ..

As far as your bubble rollers..Get the Plastic ( not metal ones ). 4"x1/4" is the tool of the trade. You can go bigger up to the 1/2" barrel .. but I find it not as Versative as the 1/4".

You dont need a Radius ( corner roller ) unless your going in deep into a channel.

When your done using the roller..take out the screw at the end of the roller and flush the inside real good with acetone.

Make yourself a 'Soak' .. use an empty coffee can and pour in some acetone before you start to put your Brushes or Rollers into While you work. If your using a bucket for your Soak..just cover it up with a few rags so the acetone does not evaporate over night leaving a chuncky gum of goo on your tools in the morning ( make sure you have enough acetone in your bucket wash to allow Some evaporation ..and make sure the acetone is Fresh.

Hope this helps some..

YD.

 

[CaptainKickback]

Re: Measuring MEKP

The Measurematic is easy to squeeze out the right amount. One problem however, is that if you leave it in the heat with MEKP in it, even a little, it will bubble out into the measuring reservoir. Not really a problem as long as it is standing upright.

So now, I just pour the MEKP into Measurematic's reservoir. Problem solved.

 

[oops!]

Re: Measuring MEKP

I thought about adding this when I posted earlier and didn't but now that they have been mentioned - when using the USC products shot glass to measure at least watch the way they are marked. After having troubles with under-catalyzing I found it best to use the ml/cc scale VS. the oz scale.

i use this same cup every day....love it...

i have 2 cups that have lasted me for 2 seasons.

use the metric system.....you dont need to be a chemist and you dont need a calculator.

the buckets you use for the resin will be metric as well.

 

[ondarvr]

Re: Measuring MEKP

I thought about adding this when I posted earlier and didn't but now that they have been mentioned - when using the USC products shot glass to measure at least watch the way they are marked. After having troubles with under-catalyzing I found it best to use the ml/cc scale VS. the oz scale.

Those cups work very well, I carry them all the time in my tech service kit. There is one a little larger that holds about 4 oz's, it works well for doing gel coat repairs, you put 100 cc's of gel coat in the cup and then add 2 cc's of catalyst. Use a calibrated eyedropper to measure the 2 cc's.

 

[TruckDrivingFool]

Re: Measuring MEKP

For reference my only point was that the fractal scale came out different on the dram cup(thanks YD) than the cc/ml when measured by other means.

 

[Cadwelder]

Re: Measuring MEKP

I use those little cups daily, I have sleeves of them (they get a little cloudy after a while). It's very simple math, 1 ounce is 29.5 CC's so if you measure out 16 ounces of resin (16 x 29.5 = 472 then 472 X 2% = 9.44 CC's or round it to 9 CC's) I've done this so much I have it memorized but it's takes 5 seconds to punch it in a shop calculator.

The bottle that YD referred to are nice also.....and the metric system does make it simple too...100 ML (about a quart) is 2 ML of MEKP. I'm not to crazy about the "drops" system as I tend to loose count or squeeze the bottle to much and get extra drops...

Anyway this is my method..

CW

 

[ondarvr]

Re: Measuring MEKP

The squeeze bottles work well in a production or repair shop, but for the DIY'er the cup works better.

 

[britisher]

Re: Measuring MEKP

Maybe a little late in the day to add this but I ordered all my restore stuff from US Composites. Just ordering online for the initial was a no-no for me and wanted to phone the order in. I spoke with Steve who is their 'tech guy'. He owns 2 boats himself and is wonderfully knowledgeable and helpful. He helped me order just what I needed and no more. He was also the guy who told me the poly resin has a shelf life of 3 months, so don't order more than you can use in that time frame. I may be a cheap skate, but I've managed perfectly well with chip brushes and no rollers. The only roller I bought was the bubble buster, which has been useful. The mixing tubs for some reason are flexible and when the excess mix has cured you can 'break it' out of the tub and re-use the tub if you want. I bought the bag of 50 sticks and I'm now on stick #2, brush # 4 of 25. I used the list that is published on the forum, but found some of the volumes are way off. It recommends 1lb of chopped strand. That went really quick, so bought a 5lb tub which should last me. The Cabosil was 5QT but TBH I think I should have doubled that quantity.

 

[Woodonglass]

Re: Measuring MEKP

Poly's shelf life is kinda variable. If stored in a cool dry climate it can last longer than 3 months.

The "List" is not intended to be a "All you will Need to Order" list but rather a good starting point. There is no way to tell exactly how much of everything any individual person will need on any given restoration. When making Peanut butter 1/4 cup of chopped strand per quart of resin is plenty. If you are using more than that, IMHO it is too much and not needed. 5 lbs of chopped strand would last a LONG time. 10 qts of cabosil is prolly about right but not everyone uses it at the same ratio. Some people on a tight budget don't want to muchf "LeftOver" so the list starts out with mimimums.

 

[62cruiserinc]

Re: Measuring MEKP

Thanks everyone for your extremely helpful replies!

I'm ready to order the supplies now. I had forgotten about the chopped strand and Cabosil, but britisher mentioned them in his post and I added them to my order list.

Steve

 

[Scott Chinsota]

Re: Measuring MEKP

for my smaller batches...4 ounces for example, I use 1cc u100 insulin syringes. throw the needles away.
no need to count drops. .94 was the exact conversion but as I got faster, I sweetened the mix. scale goes to 1.0.
guesstimate where 1.1 would be and squirt (wear goggles).

my math was based on one ounce per gallon 1/128 approx 3/4 of 1 % per my resins instructions.
1 ounce = 29.4 ml 4oz=117.6 ml .94ml = .8%
1% = 1.176ml (cc) approx 1 full syringe per 4 oz resin
1.5% = 1.76ml per 4oz = hot batch

larger batches accept the variance of a shot glass measure but for micro batches, syringes can't be beat. They're cheap in a ten pack at your local pharmacy. after a few uses, the mekp eats the rubber stopper so buy the ten pack. if you ask for u100s they'll ask 1/2 or 1cc and assume you are diabetic...they are insulin syringes. Smile and ask for a ten pack.

 

[Yacht Dr.]

Re: Measuring MEKP

There is no doubt that those Drams and syringes are Great for small little bitty batches.

I was just thinking that since the OP placed a big order..I assumed that he is doing a big job.

When doing big jobs the sqeezy bottle can save you time when your up against a wall having to make a quick batch.

Whatever you get used to is what is best to use .

YD.