Thread: Filling holes in ironbark

Your best option for filling large voids in wood is Epoxy, its the only thing that will have any strength across a void. Mix with sawdust or a mineral oxide, generally a darker filler looks better then a lighter colored filler, a good color is pencil lead carbon, you can buy the oxides from arts supply stores for about $14 per tub that will last you for many liters of epoxy.

The leading brands for epoxy used by woodworkers are Techniglue Two-Pack Epoxy Gels and West System Epoxies. Both can be purchased from Carbatec or a boating supply store. For filling voids I prefer west system as it is very runny before you mix the filler in it, and you can tailer how runny the epoxy is by the amount of filler you add, so you can make it very runny so it will drain into the deepest part of the void. But I think Techniglue is a better glue epoxy.

Id use that for firewood, failing that fill it with epoxy

Before you proceed with an epoxy fill in that size void you should cost it out, you might just change your mind.

If is is structurally sound, why not leave it as a feature. Filled with epoxy and sanded back would probably look odd.

Originally Posted by Burnsy

If is is structurally sound, why not leave it as a feature. Filled with epoxy and sanded back would probably look odd.

I'd go with Burnsy. It would make a great talking point.
Jim

I filled some voids in a red iron bark deck and used epoxy. I used HT9000 epoxy (nice and runny) and mixed in some red iron bark sawdust. I used the sawdust as I wanted to minimise the appearance of the voids. In your case I would probably mix in some black oxide and not completely fill the voids, and make a "feature" of it.

thanks all for the advise... i didnt want to completely fill the holes, just get them roughly filled.
Im with vernonv, still want them as a feature point.

thanks again for the advise

Originally Posted by thumbsucker

Your best option for filling large voids in wood is Epoxy, its the only thing that will have any strength across a void. Mix with sawdust or a mineral oxide, generally a darker filler looks better then a lighter colored filler, a good color is pencil lead carbon, you can buy the oxides from arts supply stores for about $14 per tub that will last you for many liters of epoxy.

The leading brands for epoxy used by woodworkers are Techniglue Two-Pack Epoxy Gels and West System Epoxies. Both can be purchased from Carbatec or a boating supply store. For filling voids I prefer west system as it is very runny before you mix the filler in it, and you can tailer how runny the epoxy is by the amount of filler you add, so you can make it very runny so it will drain into the deepest part of the void. But I think Techniglue is a better glue epoxy.

Hi thumbsucker,

Thank you for providing the links for those glues, most appreciated. I've been using lots of 2 part epoxy tubes (like Araldite) but of more economic brands, at about $3.00 to $4.00 per pack, at Browse & Save store. Even buying by the box, (50 packs) I only get 10% discount, if I buy a full box at the time. These glues come most of the time on the fast cure at about 5 minutes or so, sometimes they come in the 24 hours cure but they are rare to find on these less expensive brands. Filling timber voids with these tubes, (even 1/3 of the cost of the more expensive ones) can be a very damn exercise, as I have had blanks that took 2 and more packs to get around the problem.

Now, my concern with these larger epoxy glue systems, is how much wastage you get out of them, I mean, if using the recommended glue types you mention, can one use small quantities each time, and not end-up with a 3/4 full tube or tin of glue that has dried. or become useless due to the amount of times the tubes/tins were open in a certain amount of time? I understand that most of these glues "activate" only when mixed but if they are like some 2 part epoxy resin floor varnishes, I worked with in the pass, the shelf life of these products is/were reduced/compromised, every time the product gets in contact with air (oxygen), by simply opening the lid of whatever the container these products come in to.

What is your opinion on the products you mention above, under my concerns "banner" ?

Now, in relation to mrtayls enquiry, if the posts are structurally sound, I would stabilise/harden the soft tissues rotten, after a good wire brush clean. Obviously, restoring some of the natural timber "hardness" in those damaged areas, by simply pouring a small layer of these epoxy type glues, on the the "holes", is sufficient. One other "trick" that I would suggest is, due to the fact that most of those glues dry clear and glossy, instead of mixing anything with the glue, I would get some saw dust from that same timber (handsaw saw dust is ideal), and "sprinkle" the fresh glue with this saw dust, in a very "generous manner", in other words cover the glue with it, and leave it to dry. Only some of this saw dust will stay stuck in the glue after dried but, and after cleaned (air gun, brush, etc) the surface of the glue will be covered with the raw saw dust from that same timber, making the glossy, plastic look from the glue disappear, and make it look like just the rest of the log (maybe a little lighter in colour, which can be fixed easily). Because the holes weren't completely filled up level, the area will still look a natural feature, just not as deep and with a strong and water resistant "skin", making the log to last another 100 year...!

Cheers
RBTCO

you had better stick some reo in there to give it some strength.

they aint going to move, the posts are 180x280 and the rot is only on that one side... theres still a good 200mm of solid timber to keep it structural.

Does any body know where i could buy that HT9000 from? I live in keilor, just near the air port in the west.
cheers again

Originally Posted by robutacion

Now, my concern with these larger epoxy glue systems, is how much wastage you get out of them, I mean, if using the recommended glue types you mention, can one use small quantities each time, and not end-up with a 3/4 full tube or tin of glue that has dried. or become useless due to the amount of times the tubes/tins were open in a certain amount of time? I understand that most of these glues "activate" only when mixed but if they are like some 2 part epoxy resin floor varnishes, I worked with in the pass, the shelf life of these products is/were reduced/compromised, every time the product gets in contact with air (oxygen), by simply opening the lid of whatever the container these products come in to.

I have have mixed teaspoon quantities of "these larger epoxy glue systems". As long as you get the ratio right you can mix even smaller. As for the remaining unused epoxy, I have had bottles sitting 95% empty with lots of air in the bottle, and the epoxy was as good as the day I bought it a year later.

The Epiglass HT9000 comes from Bias Boating Warehouse and probably any other boating supplier, not sure if there's an outlet near you but they'll likely do a mail order if you want. The hardener is classed as dangerous goods so shipping can be a bit steep.

I'm not an expert on this stuff but I have done a bit of composite molding as another hobby and recently compiled a bit of information on various epoxy resin systems that were available to me and the cost of each. I've attached this information as a pdf file for anyone that is interested. The suppliers and locations were those closest to Sydney at the time but if you check the suppliers websites many of them have state distributors.

All of my mixing is done on a small electronic scale and I've mixed quantities between 2 grams and 200 grams at times. As thumbsucker mentioned, they will keep quite well as long as you reseal the containers. I've decanted both resin and hardener into smaller squeeze bottles for easier mixing and have not had a problem with their shelf life.

The one thing you may want to consider when using these epoxy resins is the cured colour, since most of these are laminating resins they're not necessarily designed to cure colourless. Some have a slightly yellow tinge when cured, some blue and some are clear. I'm not sure about the HT9000 but a little research should find you the answer pretty quickly. Casting resins, specifically designed for a clear cure could be more suitable for your use.

Originally Posted by stevemc32

The Epiglass HT9000 comes from Bias Boating Warehouse ...

That's where I got mine.

All of my mixing is done on a small electronic scale and I've mixed quantities between 2 grams and 200 grams at times.

I do all my measuring using syringes (20ml) and mix in disposable cups with tongue depressors (syringes and tongue depressors bought in bulk from an online supplier).

Some have a slightly yellow tinge when cured, some blue and some are clear. I'm not sure about the HT9000 but a little research should find you the answer pretty quickly. Casting resins, specifically designed for a clear cure could be more suitable for your use.

I have only used a little HT9000 for "clear" applications and I seem to recall that is quite clear (maybe not "glass" clear though) - however if you are mixing in an oxide (or other filler) then clarity is not an issue.