Problem with resin curing too soon

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#1

Well my latest problem is that my resin isn’t travelling fast enough/curing too soon, different sides of the same coin I guess.
I’m using VER catalyzed 1% mekp around 20 degrees celcius.

even with the red resin flow media (4 lavers of glass and some coated peel ply) the resin doesn’t seem to travel fast enough.

what should I do?

More flow channels?

Less catalyst?(but will is still cure?)

Different resin with lower viscosity?

suggestions?

despite this I still managed to get this nice undertail out of it:D ! but it was a pain in the ass cause I had to cut holes in the bag and then lay more strips of flowmedia and new resin tubes and then seal over all of it with mastic:mad: more work then I’d like to talk about and I would like to avoid such frustrations…

#2

Might be worth looking at the amount of vacuum you have, and whether or not the resin you are using is specifically intended for the RTM process?

#3

holy snap that really didn’t travel!!

what specific resin are you using? What kind of glass as well.

as classicbike said what is your vaccum level?

#4

Hey i would suggest double up on the flow media. his vac looks good.

#5

it is hard to gauge. On something like that I would only use about 1/8 the flow media he is using and the whole part would infuse in about a minute and a half and I would have like 20 minutes till it kicked. I am infusing a pair of door inserts and I will record it to show the flow media I am using and how fast the resin is traveling. I use an orca infusable VER.

#6

Dude its got to be the resin your using…how long till it kicked off?

In my experience if your resin calls for a 20 minute work time, while under vacuum it will have a 30 minute work time.

The stuff in the cup gels faster than the stuff on the part for me and thats when the cup is nearly empty.

I use smaller lines than that (i think my lines would fit in yours) and I can infuse twice that size of part in 10 minutes.

Granted I still use full coverage of flow media like you do and I really need to buck up and use the bigger lines. Its just alot cheaper for me to do it the way I do in the long run.

#7

Every resin manufacturer has a min/max % of catalyzation. Call up your resin maker and ask them the bare minimum % of hardner needed to get the resin to cure.

#8

If a resin intended for hand lay up rather than RTM is being used (which wont be thin enough for RTM), then this may well be the root cause of the problem.

RTM resins are in general far thinner, than hand lay up ones, and this is something that is easily noticed, after working with both types of resin.

Its always a good idea to discuss what you want to do with your supplier, and make sure they also send a tech sheet with products like resins, so you know exactly what you have, and all the info about it to hand when you are using it.

#9

The resin I am using is the VER 8084 by derakane (sp?) some people on here suggested it and said they had success with it. The viscosity is in the 300-400 range. It was about 10-12 minutes by the time it really stopped moving through the materials.

I am having no luck with local retailors as far as finding a suitable infusion specific resin, they don’t really know what to offer around here…

#10

20 degrees celcius might have thickened up your resin a bit. Thats a little chili. But then the rule of thumb is that at that temp it should have slowed your cure by half. So who knows.

I still say use less hardner. Like 3/4%, or 1/2% if the manufacturer says its safe.

A prime example would be your generic Bondo Polyester. They recomend WAY to much MEKP. You can go way under what they recomend and get great working life with it. Disclaimer: I only use Bondo Poly for prototyping, and quick wet layups.

#11

Its a bad mistake to base using a particular product on whats contended on a net forum!

In the case of resin systems its very easy for your local supplier to contact the manufacturer they deal with, and ask them to recommend a specific product. If they cant be bothered to do that, then it might be better to use a supplier that is willing to help?

Regarding the resin you have I would suggest contacting the manufacturer direct, and ask to speak to thier tech department, and see if they are able to help.

#12

thanks guys, I will contact the manuf and get the info on the resin

#13

What measuring device are you guys using to get exactly 1% of MEKP to resin ratio?

I bought a graduated suringe… will that work well or no?

And then is it 1% by weight or 1% by volume?

And where can i buy an accurate scale for cheap? I plan on working with epoxy and PER…seperately of course:D

#14

Don’t be afraid to double up on flow media if need be. Also, are you using any type of tee or anything at the end of the inlet tube? If you are using nothing at all, put some flow media on top, right at the end.

#15

Your local “head” shop…:rolleyes: or eBay.

#16

I use a squeeze bottle with the cup on top of it for measuring MEKP.

Use the catylization chart on fiberglast.com for reference.

By weight or volume is manufacturer specific. Call the manufactuter and ask if your unsure.

You might think that the weight vs. volume wont make a difference. A really good example of how weight can vary is Duratec’s base primer vs. it surfacing primer. Both measured at a volume of 28oz are about 5 oz off by weight.

#17

Say i’m using 6 fluid oz. of Bondo brand polyester resin. How many drops of MEKP would put the ratio at 1%? Using an eye dropper.

There has to be simpler way of getting the ratio correct than weighing it out?

I have a digital scale that measures in 1/10 ounces and goes from 1/10oz up to 50lbs.

#18

On that scale: What is the + - % as the more max. weight, the more % off.

Gel time Test by using 100 grams of resin (without cup, tare it) and add say 10 drops, mix and watch it goes thur the A (liquid) to B stage (starts to gels up) and that is your working time.