Varnishing - "Sanding Sealer"???

[David_Old_Jersey]

Epoxy and sawdust? - I can see that going well with me - I think you just want to see some photos of me with the lid stuck to me hand

I'm gonna stay with my solution - how hard can it be to do any damage with what is just a glorified CRAYON???



(apart from sticking it up me nose or in me ear. Been there and done that longggggg ago! )

[Alan Wheeler]

Hi Wotname. Can you tell me if there are any tricks to that remedy. I have tried Epoxy a Sawdust as a filler many years ago. And it was a dismal failure. First of all it would not cure. It took ages to harden. I could not work that one out at all. I even tried another brew of it in case I had made a Hardener ratio mistake and the same happened again. Then when it finally did cure enough to sand, it looked terrible, as the epoxy dust mix goes too dark. So I ended up painting the piece I was working on. I never used Sawdust again after that event. So if you have had a positive result, I will give it another go in case I really did do something wrong.

[Wotname]

Interesting, I haven't had that problem but then again thinking back, it has been about 15 years since I last used it. OK perhaps I having making less mistakes than I used to (or have gotten over being a perfectionist).

Can't remember what epoxy I was using in those days but it would have been WEST or International HT 9000. I think I made up a white(ish) sanding (soft) filler epoxy mix and added the dust for colour.

I will be mixing up some Bote Cote today or tomorrow and will try a couple of experimential mixes and report back.

I wonder if you had some unknown contamination in the sanding dust. FWIW, Bote Cote suggest that a heavily oxidisied wood surface doesn't adhere well to epoxy and as sanding dust would be very oxidisied (I think), there may be something going on around that - can't really see though .

[Alan Wheeler]

It is quite possible it was the wood that created the problem for me. I was filling with Teak wood dust. Maybe the waxy nature of teak stopped the stuff from curing properly.

[Wotname]

Yes, maybe...

OK the results are now in. I mixed up some Bote Cote epoxy and added several combnations of fillers; a sanding filler - SF - (BC brand), fumed silica - FS - and some sanding dust - SD - (about 3 weeks old, combination of Aussie Hoop Pine and a SE Asian rainforest hardwood - Nyotah). BC epoxy is a Aussie 2:1 ratio, 100% solids epoxy formulated especially for wood bonding and encapsulation (and NO amine blush - whatsoever)

Baseline was pure epoxy and then lumps of SF, FC, SD, SF+FC, SF+SD, FC+SD, SF+FC+SD; They sat in the sun for 2 hours and moved indoors as soon as the sun set, ambient temperature was around 20 C.

The curing speed (as measured by the resistance to my fingernail) was proportional to the colour on the mix; however they all cured within say 25% of each other. As per Wheels experience, the sanding dust and epoxy was very dark and the colour was not controllable; however, unlike his experience, this sample cured the fastest (I assume due to the solar radiation - sun )

The fumed silica filler was white and the BC sanding filler was off-white. The addition of the sanding dust made each mix somewhat darker and the degree of darkness was quite controllable by varying the amount of sanding dust. The cured colour was about the same as the uncured colour.

Over to you, Mr Wheels .

DOJ, looking forward to a photo of your hand stuck to the lid

[jamestfisher]

Also interested in this thread... I've just stripped (with heatgun) all the varnish off my teak interior floor and would like to re-finish it... but i'd like to make it as light as possible.... what is the best finish to use? I was planning on a light sand followed by teak oil - but not varnishing... do I need to varnish, and if so - am I better just using a clear varnish after the oil or no oil?

Thanks for any input!

James.

[imagine2frolic]

jamestfisher,

Look at post #18

I hacve friends that use sawdust as filler with the West System. West says it can self combust? Any one have experience with self combustion?

[FrankZ]

Originally Posted by imagine2frolic

jamestfisher,

Look at post #18

I hacve friends that use sawdust as filler with the West System. West says it can self combust? Any one have experience with self combustion?

I haven't had selfcombustion though I was working with the fast hardener one day, about 85 degrees out, and when I quit stirring it started smoking after about 10 seconds. I dropped it over the side, on the ground. It did get very very hot.

[Alan Wheeler]

Sorry Wotname, I missed your reply till now. Excellent experiment. And I am happy you had a better result. So maybe the wax really is the issue with the cure time. Or of course, I could quite possibly have stuffed up the mix ratio.
As for self-combustion. Yeeeup. Many a boat shed as been set ablaze due to the stuff getting so hot it catches fire. You need to use more open containers to allow the mix to let off heat. On very hot days, the work time can be extended by placing the mixed resin container into another slightly larger container of cold water. On very hot days, you can place both Resin and hardener in the fridge, which allows you to start off the mix with cold liquid. I have also placed over mixed quantities of epoxy paints and evadure in the Feezer to extend the working time. I saved an enter 4ltr (1Gal) mix once by a long story, but someone mixing the two parts together all at once. I was able to paint the coats on over several days. However you need to ensure the tin is well sealed to keep moisture out. Oh and from one situation I learn't the hard way, don't place two pot paints in the freezer uncovered when there is food in there. That was an expensive lesson.

[Wotname]

Yup, lots of issues with exotherming epoxy - another reason why one shouldn't use glass containers for mixing the stuff - they break rather suddenly if they get too hot.

It's OK Wheels, I got over my hurt feelings

BTW, which frozen food ruined the 2 pot paint!!!!!!!!!!