Grain Filling with West Systems Epoxy

[Graham Long]

I've been using west systems epoxy on my latest builds, all looking good - until the last lot that went on today. Some of it remains sticky, can't see any obvious errors, it was weighed out for a 5:1 mixing ratio and mixed well.
Has anyone had a similar problem? And does anyone know a fix?
Cheers
Graham

[kiwigeo]

How are you measuring out the quantities? I believe with the West Systems products the quantities have to be fairly precise. I use syringes to measure out the resin and hardener (by volume).

I also put a small amount of the mixed up resin into a small plastic cup and leave it to set.....if it sets hard then I know its going to be doing the same on the guitar.

[Graham Long]

I've been using a set of digital scales, which probably isn't as accurate as your syringe method.
The left over resin set rock hard, not sticky at all.
I'll let it sit a bit longer before doing anything rash.
Cheers
Graham

[Trevor Gore]

If you're using a 5:1 mix ratio, you're looking for trouble!

For grain filling or clear coating you should be using 105 with 207 special coatings hardener, which is mixed 3:1. 105/207 will always remain clear (in my experience - as it says on the can), whilst with the 105/206 (1:5 mix ratio) you risk it going white on you down the track, sometimes a long time down the track. DAMHIK.

The only reasons I can come up with for the mix not going off on the job (when it did in the pot) is contamination or too cold, but both seem unlikely. 105/207 tends not to leave any residue (for want of a better word) on the surface, whereas you can get a waxy film when using 105/206, which is an amine blush that forms as part of the curing process (and is fairly normal with 105/206).

If it doesn't harden up, the fix is to get it off.

[Allen]

It's happened to me a couple of times. And several others I know have had the same problem. And I know that my mix was spot on, as I use a very precise digital scale to the .01gm. Always on small mixes. It's certainly not the cold up hear in Cairns either.

The only fix is to scrape it off or any other method that works for you.

I've switched to using Bote Cote now, and every time it works a treat.

[Graham Long]

Hi Trevor,
Thanks for that. I checked it this morning before heading off to work, it's cured and sand-able
But I'll take your advice on the 206 - so Bugger - Off it comes then, and I'll get some 207 hardener
Thanks again, I'll let you know how it turns out
Cheers & Thanks
Graham

[Graham Long]

Hi Allen,
Thanks for chiming in, I have some Boat Coat, near full bottle in fact. As with all of my epoxies it's been kept in the fridge, one part has gone quite thick, still pourable but like very thick cold honey.
I haven't used it for 12 months or more, I'll mix some up this afternoon to see if it's still viable.
Cheers
Graham

[demonx]

Only time I've run into trouble with the West Systems is when I had it on too thick.

I learned it prefers multiple thin coats rather than one thick one.

We have to try these things!

[colburge]

It's happened to me a couple of times. And several others I know have had the same problem. And I know that my mix was spot on, as I use a very precise digital scale to the .01gm. Always on small mixes. It's certainly not the cold up hear in Cairns either.

The only fix is to scrape it off or any other method that works for you.

I've switched to using Bote Cote now, and every time it works a treat.

It has happened to me several times as well (not on instruments), and I was positive I weighed it out correctly, I had no idea why, but thought I must have had too many beers. Scrape it off and try again.

Col

[Graham Long]

Sounds like West System Epoxy isn't all that reliable.
I've since taken it all off and ready to go again, I think I'll go with Bote Cote this time.
Thanks everyone for your help, much appreciated, I'll post some pics of the finished product
Cheers
Graham

[DarwinStrings]

I guess I have to listen to this and wonder what is going on. I have not used it as a filler but I also have had no trouble with it. One thing I have noticed is that in general I am looking at around 48 hours for a full cure (manufacturers test) and that is the left overs in the pot so that leaves me wondering if the problems that are occurring are related the the use of it in the very thin layers that are used for grain filling. That is that the thinner it is the less it heats up and the slower it cures. How long have you guys been leaving it before you decide that it has not worked?

Jim

[Mike Thomas]

I wonder too, Jim. I have been using West Systems epoxy for about 20 years, mostly laminating carbon fibre or veneer, and have never had any issues with it. I have always made sure that it is in a warm environment whilst it's curing, if necessary covering the work with an electric blanket.

[Graham Long]

Hi Jim,
I had applied several coats of WS Epoxy. the first ones cured fine and were hard and non sticky within hours of being applied. The third coating was still sticky the following day. However went i went to remove it, (later that day) it seemed to be OK, but I removed it away seeing as I had used the wrong hardener.

I too have used WSE for laminating etc without issue.
I'll get some 206 Hardener and give it another go as a grain filler, leaving it to cure for A longer period
But I'll finish these two Guitars with Bote Cote.
Cheers
Graham

[demonx]

To anyone that is having trouble due to mixing ratios, why not spend a few extra bucks and buy the pumps?

If there is a way to stuff something up then I'm usually the guy to find it, but with west systems its as simple as one pump from bottle a and then one pump from bottle b. It's that simple.

As I mentioned before, the only time I've stuffed up with west systems is when I tried to cake it on extra thick hoping to not have to do a second session if grain filling. That's my fault not the products fault. Lesson learned, west systems likes multiple sessions with thin coats, not super thick coats!

[rocket]

I've had my share of issues with Wests as a grain filler in the past too so with dark coloured timbers i've been using Timbermate with some success, but my current build is Maple back and sides with a blonde finish so i'm thinking of trying the Botecote product, is that the correct spelling? i'll have to find a supplier in Melb.
Rod.

[woodrat]

This thread is of interest to me because I am about to grain fill two guitars with epoxy for the first time. I am using West Systems and have the 207 hardener so hopefully all will go well....I would not like to be scraping it off two guitars thats for sure....

Rod...I tried Timbermate on a rosewood guitar last year.....I used Black but it was more like dark grey when I finished over it....I didnt like it at all and took the lacquer off after a couple of coats and washed the TM out of the grain....I still use TM a lot for small filling but not grain fills...



John

[demonx]

I have to agree with woodrat, I also dislike the timbermate and only use it when I have to.

I'm using it at the moment on five guitars only because they are to be finished with Danish oil rather than a clear coat. If they were to be sprayed, it'd be the west systems in the grain for sure.

Another product for consideration would be forms of CA glue (superglue). I've heard of people using this successfully as a grain filler. I've only used it for spot repairs and it works quite well so if you were to find a bulk supplier I'm sure you could grain fill with it as long as it's not too runny.

[Clay Schaeffer]

"For grain filling or clear coating you should be using 105 with 207 special coatings hardener, which is mixed 3:1."

If you are mixing by weight the ratio is different for the 105/207 combination. I believe it is 3.7:1 by weight , but read the can - I'm in N.A. , so maybe it's different in Oz.
I use a triple beam balance to mix epoxy by weight. I have used the pumps in the past, but they are less reliable for small amounts

[Jeremy D]

"For grain filling or clear coating you should be using 105 with 207 special coatings hardener, which is mixed 3:1."

If you are mixing by weight the ratio is different for the 105/207 combination. I believe it is 3.7:1 by weight , but read the can - I'm in N.A. , so maybe it's different in Oz.
I use a triple beam balance to mix epoxy by weight. I have used the pumps in the past, but they are less reliable for small amounts

I was going to mention this too. The guys at boatcote explained to me that their product has a different ratio by weight also. I ended up just buying seringes from the chemist. Worked very well.

[simso]

Start saving the bickies and go UV. Under a minute from raw wood to pore filled and sandable.

[Trevor Gore]

Steve, is your UV system based around a polyester compound as a filler?

[woodrat]

Had my first go at the epoxy pore fill today....two guitars too....I am looking forward to the results

3 hours and the fisrt one is touch dry... so that is a good sign...

[simso]

Yeh trev its a polyester based filler, the system and paints we use are the exact same ones that prs use.

[Trevor Gore]

Thanks, Steve.

[56nortondomy]

I use timbermate sometimes and it's like what the other guys are saying dark grey instead of black, so today i added some black tempera powder to it and it seems to have done the trick, i used it to fill the fret end holes on an ebony f/board. Turned out really good. Wayne