Applied West system mix 5: 1 to board 4 days ago to some nicks and scratches, no filler/microbaloons, or matting- had not set hard, but was not tacky, sort of rubbery by last night.
So brushed over with hardener, now its still the same.

How can I:
remove it and start again?, or
get it to set ?

Hey Toby,

Acetone will remove it if its still wet, dont know why it hasn't gone off though? the temp lately hasnt been overly cold?

Try sticking a heater on it (not too close) if you wanna try to set it. Did it start to cure or is it still completely wet?

Edit: just read your post properly I think the heater will work, It takes longer to set if the teperature is down, full cure can take up to a week.

thanks Luke- will try all of the above

but more comments welcome from the community.

Was it 105 resin and 206 hardener?

How was it measured?

yes 105 and 206.

measuring method: tongue angle 45 deg- a splish and a splash into a small container!

( i am hearing some screaming and " serves you right !" about now .)

Epoxy has to be measured very very accurately. Otherwise it won't harden, Scrape it off clean with acetone, clean again with acetone and start again.

ACETONE?

Better be 100% sure the damage hasn't gone through the glass or your going to melt the foam core with acetone, if it ain't gone off just srape it off and do it again..

Just mix it properly, don't do all the hack jobs like pooring more hardner over it and all those dodgy things if it don't work.

Go to The shops and buy a mixing cup, even one you use in the kitchen will work.. and try to not do it when it's too cold..

Toby it is 5:1 by weight........ not eye

As the two parts have different densities the only way you can do it by volume is using the West Systems pump measure (not worth buying that for a small job).
Find somebody with digital kitchen scales that does 1g increments

Yep epoxy is not like polyesters, you can't vary the ratios, and as you found 'hot mixes' are then a waste of time and money. Easiest way for small jobs is to get your mixing stick and mark the depth you want onto the stick for resin and then hardner, leave the stick in the container and pour with confidence. (make sure the container is properly cylindrical, not a coke bottle offcut). Alternately for steel containers you can measure up from the bottom flange on the outside and mark with a pin-punch which is then easy to see on the inside surface as you pour.

I use a syringe for small quantities. It has a grduated measurement on the tube so you can get a reasonably accurate measure.

I always seem to do my resin work late afternoon and have alot of trouble with it hardening because of the temp at night.
You really need a good hot sun, give it a hit with a lamp or heat gun from a small distance. Make it nice and warm not too hot that you can't touch and hold. Will be set after that

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Troyrotor said...

I always seem to do my resin work late afternoon and have alot of trouble with it hardening because of the temp at night.
You really need a good hot sun, give it a hit with a lamp or heat gun from a small distance. Make it nice and warm not too hot that you can't touch and hold. Will be set after that

Properly mixed epoxies with a normal rate hardener should go off no problems in anything over about 15deg.

The above is not good advice for boards with styro core as the amount of air in there causes expansion and the air can try to escape thru your repair thus bubbling the resin and sometimes pushing a layup away from the surface. Best done on a falling temp, I do almost all my repairs about sunset.

Yer go and buy a set of $100 digital scales for a 2cm repair, well worth it..

5:1 is 5:1

50grams to 10 grams, 50ml to 10ml. i'm not genious but pretty sure it's still 5:1

The syringe is a good idea, works really well..

It's only a ding so measuring cup or similar is fine, strength is not an issue so a small % of actual strength loss from not using scales won't be a problem..

Epoxy will stay sort of soft when it's heated directly so i would stay away from a heat gun, maybe in a room with a heater so it's not a localised heat on one spot is the go..

I got the scales- thanks Mrs in the Kitchen

Its feeling dryer with the brushed on hardener, I'm gonna wait a few days then see what happens.

Thanks everyone- looks like I just gotta change attitude measuring technique next time !

I guess everyone else has replied, and you have now learned it is important to mix it by volume or weight, not by eye

I use the west system pumps for normal jobs, and syringes for small jobs, myself. If I am running low on resin or harder I resort to the electronic scales. Syringes are cheap, and its it worth the funny looks at the chemist when you ask for forty 20ml syringes and forty 5ml syringes.

There is a hardener for West Systems that's 3:1, but it's unlikely you are using it, as it is meant to be a UV stable epoxy.

@ PC, actually if you read the West system literature the ratio is specifically by volume not weight. If you're using weights it's not a simple ratio. I always buy my resin from companies that use a ratio by weight as I use scales but West isn't one of these companies.

Edit:- http://www.westsystem.com/ss/typical-physical-properties/

Note the different "by weight" ratios depending on the different hardeners. I can't remember which is the "standard" hardener. Looks like they've changed to a simple by weight ratio for the slow 206 hardener.

Volume measuring is spot on for 105 resin and 205 (fast) or 206 (normal) hardener which is what most people will use. Weight is damn close as the densitites of the resin and hardener are similar. So u can do it either way.

I measure by weight so I don't go thru lots of syringes, and I can't accidentally use the resin syringe in the hardener, and I have kitchen scales that are accurate enough.

It changes for 207 (super slow) and 209 (UV stable?) hardeners..... ratio is 3:1.
BUT the density of the hardener is different so if measuring be weight it is 3.5:1

Not all resin systems use similar density fluids so for some u have to use volume or others use weight, and if you want to use the alternative method you have to calculate based on density.

+1 on the syringe idea.

I've been doing some castings using a very thin epoxy, when I did things by eye I would lose about a quarter of castings due to it not going off properly (despite holding my tongue in _exactly_ the right way), but now using syringes I get it 100% right, 100% of the time

The chemists do look at you a bit funny, but tend to relax when you say you don't want needles to go with the 30 syringes

Also, mark your syringes (resin or hardener) and put some sticky tape over the markings BEFORE you start sucking up the gloop -- if it gets on the texta it will remove your markings.

Another handy tip use bote cote its easier to use.

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Bender said...

Another handy tip use bote cote its easier to use.

if your talking about its easy to apply because it doesnt run everywhere ill have to agree, i went to laminate a board and i couldn't find the instructions on how to get the stuff out of the container after using 1/2 the contents, i'm sure it has a shelf life , ended up getting some west

PS my scales have 4 settings from 1 gr to 5 klg the max

+2 on the syringe Obi.
Done a few repairs of varying sizes and haven't had a failure yet.
Different sizes available from chemists.

This trick works for me every time.

Get a heat bag (the wheat filled ones), warm it up in the microwave.

Cover the glassed or resined area with glad wrap.

Put the heat bag over the repair and cover with a towel to stop heat getting out too quickly.

Don't get the heat bag too hot or it will thin out the resin causing it to run and form voids in the glass. Foam in the board insulates from the inside towel form the outside so it stays warm long enough for the resin to set.

I have used an electric blanket in the past and that works a treat as well, hot water bottle should be OK as well but the wheat bag conforms to complex curves better and applies a more uniform pressure.

Good luck
Derek

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Wayne said...

+2 on the syringe Obi.
Done a few repairs of varying sizes and haven't had a failure yet.
Different sizes available from chemists.

buy the ink refill syringes, they offer alot bigger sizes and have a much larger thicker non sharp needle

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choco said...

Wayne said...

+2 on the syringe Obi.
Done a few repairs of varying sizes and haven't had a failure yet.
Different sizes available from chemists.

buy the ink refill syringes, they offer alot bigger sizes and have a much larger thicker non sharp needle

Or...visit your local vet, I did & they 'gave' me about 6 syringes (3 diff sizes) from large to small. No good to them, something about gone past date or no longer sterilised?!