Epoxy - Question of life

[Christos]

I have never used epoxy to fill holes in wood. I have a few holes that are from 1 to 8 millimeter wide. Some going all the way through the wood.

So this could be a good time to try out something new.

I have read on this forum about what people use and have some idea of what I will get. That being said and with me not actually sure on a few things some questions come to mind.

I want to know what people think of the brands they have used? How well it took colour? If the colour faded over time? From where to purchase the colour (liquid or powder)? What the viscosity is? Depending on brand will it fill holes in one application or several application? How long is the shelf life?

Please feel free to add anything that I might have missed.

P.S. Should also add how well does is sand or plane?

[joe greiner]

Regarding shelf life, I've had good and bad luck. Manufacturers are at the mercy of vendors to rotate stock, and the date codes are not always accessible before purchase, regardless of vendors' diligence. JB Weld is reputed to have unlimited shelf life; Loctite (Henkel) is one year; Permatex two years. The Permatex date code is printed on a flange which protrudes from the back of the blister pack. The Loctite (last I checked) is printed on the back of the label, inside the package. The packages may have a toll-free telephone number for assistance in deciphering the codes, which are similar but not identical.

JB Weld is opaque, grey when mixed and hardened. The "clear" epoxies generally fade to amber over time.

I use 30- or 60-minute formulations for working time. The 5-minute doesn't allow much working time, and takes a day or two to achieve rigidity.

3M has a variety of very low viscosity epoxies, but I don't think they're available at retail, or in small quantities. Bright orange at that. Mostly used in the construction and manufacturing trades.

Sources: For Loctite, Home Depot and Lowes up here; probably Bunnings for you. Permatex at auto parts stores. JB Weld almost everywhere.

For best adhesion, I rout the holes with a dental burr, or a small router bit, in a Dremel to remove punky wood. Undercutting can enhance purchase.

I don't add colour per se. I usually mix coffee grounds (fresh or spent), metal powder, or key-cutting shavings (usually brass and/or aluminium) into a mortar for filling. Some folks like to use crushed stone, turquoise in particular. Soft additives work best for finishing; harder minerals may be difficult to cut and sand. I like to fill the gaps proud of the final surface, then make the last cuts and sand flush. I don't think it matters whether the holes are filled in stages or all at once, although large holes might benefit from staged filling to reduce thermal shock.

Some stunning effects might be had with combinations of the additives, but I haven't gotten a round tuit yet.

Cheers,
Joe

[cultana]

The last time I had holes to fill similar to your hole range I just used Araldite. It was/is the only epoxy available for me anyway. Any other varieties cost too much to get shipped in.

Since I was patching timber I got hold of a scrap of the same timber and weather age and used a harsh #40 paper to get some fine sandings. Mixed that with the epoxy and used that in the holes. With big holes widen it out as Joe mentioned. I also tape over the bottom so it does not run through. Again it pays to leave some glue proud, both sides where possible, of the filling and sand it back.

So far I have the only colouring I use is fine sandings. If I need a variation I mix up different sandings to get the necessary match. This means I have a whole bunch of little tins of different wood sanding colours.

[Christos]

Come on people must be more then just two who use epoxy to fill gaps.

[m2c1Iw]

What sort of wood, what type of look are you trying to achieve.

There are many types of epoxy 1:1, 2:1, 5:1 along with hardeners, have a read of the Bote cote site Welcome to BoatCraft Pacific
this will give you some hints. I've not tried it but the Poor on Gloss might be good in this application.

For filling holes and voids I believe casting resin maybe a better choice as it stays clear, Bunnings have it but I've never used it.

My results with epoxy for filling surface defects has not been good as it is an adhesive first and foremost. It will go opaque and it's difficult to get a bubble free fill (a hot mix helps better viscocity).

It's better if it is coloured and there are many options from ochre, paint tints, wood flour, Feast Watsons Prooftint plus the tints available from the epoxy suppliers although the colours are a little limited.

Hope this helps a bit, experimentation on some test pieces is the key.

Cheers
Mike

[cultana]

pour on Gloss and such similar epoxy products are very liquid and are designed in general to provide a horizontal surface. Not a good filling product for your use.

But you did not mention what you are filling besides wood, ie what is the end item?

Here:
https://www.woodworkforums.com/f187/m...ml#post1045540
The top has epoxy, Araldite, fills in the timber. They are sort of obvious as they are a pale gray colour from being sanded. Once pained with either an epoxy or poly the correct tone of the patch will come through. These are made using the 5 min Araldite mixed with fine sanding dust. They will not yellow as the main colour is natural timber so it also blends with the main timber better than using some other colouring process.

Also in this picture:

The top piece , left top corner has been patched using standard Araldite and sanding dust from a piece of the red timber top cap. It is not noticeable.


I have a few other pieces completed that I have done in a similar way, I could post a pic or two if you need a closer look see.

[Mr Brush]

I use Techniglue (fairly thick 2:1 mix epoxy, easy to keep bubble-free), and keep a few assorted small bottles of FW Prooftint for colouring where required. Works a treat, and the colour seems to last.

I used to stuff around making fine sawdust from the same timber I was filling and mixing it into the epoxy, thinking it would be the best colour match. Doesn't really work IMHO - the mix comes out a much darker colour due to the epoxy anyway, and you can get as good or better colour match using Prooftint.

The small bottles of Prooftint are perfect for this, and are so cheap that you can keep a few different light/dark tints handy.

[Christos]

Thanks for the replies fellow wood workers.

I have been doing a bit of research on some epoxy products, mainly by the web sites of the products. What I am not able to locate easily is how long a shelf life a particular product has after it is opened.

Lets say that I go and buy brand x use about 10 percent of the product and then put this on the shelf. I may need to add colour(tint) and leave that on the shelf. What are peoples experience with the brands that they used and how long did they leave these on the shelf before using them again? Were they usable after the period of leaving them on the shelf?

[Christos]

But you did not mention what you are filling besides wood, ie what is the end item?

Here:
https://www.woodworkforums.com/f187/m...ml#post1045540
.

I am building a fish tank stand. https://www.woodworkforums.com/f11/fi...ogress-116728/

And just like you on your above thread slow progress.

[Ozartisan]

Christos
I have had excellent results using West System epoxy. (No5)
Have stored & used it successfully after 12 months.
Once cured properly (at least 24 hours - 48 if you can) I found I could plane, sand, polish quite well.

[m2c1Iw]

Thanks for the replies fellow wood workers.

I have been doing a bit of research on some epoxy products, mainly by the web sites of the products. What I am not able to locate easily is how long a shelf life a particular product has after it is opened.

Lets say that I go and buy brand x use about 10 percent of the product and then put this on the shelf. I may need to add colour(tint) and leave that on the shelf. What are peoples experience with the brands that they used and how long did they leave these on the shelf before using them again? Were they usable after the period of leaving them on the shelf?

From my reading most of the epoxy adhesives have a long shelf life. Having said that I have seen manufacturers quote as low as one year and up to several as in five plus.
The experience from hobbyists/boatbuilders that use the products infrequently is the shelf life is long up to ten years.
Georgeon Bros/ West System say five years and that the resin will thicken and the hardener will darken in colour but the adhesive qualities will be unchanged.
Most professionals probably do not have quantities for long periods or if they do they would dispose of anyway so any risk to quality and durability is removed.

If tinting add only to the quantity of resin intended then add hardener after mixing if this procedure is followed a tinted batch of resin should last indefinitely.

I use both paste/Techniglue and liquid/Botecote and have product sitting on the shelf for over 3 years and would not hesitate to use it.

Cheers
Mike

[Frank&Earnest]

Since reading Joe's advice about 2 years ago, I am doing what he said above. I bought two tubs of 1+1 epoxy, 1/2 kg each and used about 10% of it so far. For our purposes, my guess is that it will last 10 years as Mike says. As colour goes, I go for coffee as it looks as a sap streak or knot. I only match the color for hairline cracks and for that I go for CA and same wood sawdust.

[REBZZ]

Most Epoxy will last indefinetly provided the lids are kept airtight. In saying this there are a small amount that will have a short shelf life, a good test would be to mix some up and if it cures it will be fine. Manufactures must put a shelf life on products to retain some quality control. I have and use epoxys at home that are 10 years past there date and still retain their adhesion qualities. If you need any advice in Adelaide contact Resimax and they will help you out.

[old pete]

Hi Christos,

Best to use one of the marine epoxies available from ships chandlers. I use British Paints brand 'Epiglue' for all my gluing and filling.

I never try to simulate the color of the piece being repaired Just doesn't work unless you want to follow up with a one or two hair brush and paint on the grain to match the local grain. Use a color that gives a contrast that makes a statement.On Blackwood for example i'd use a deep green that looks terrific.

For color I use dry paint colors form the local art supplier and I add plenty to the mixed epoxy so the color is dense and perhaps more importantly it makes it much easier to sand the job after it has cured. It's pretty difficult to sand off straight epoxy filler from soft timber such as Huon Pine without sanding to much off the surrounding area due to the differential density involved. The sanding dust is pretty obnoxious so use appropriate PPE mask.

Another technique is to use clear casting resin available from scientific suppliers or fibre glass shops and within this to embed colored stones and other artifacts of your choice. I never do this because i suspect our dinner guests would find the table more interesting to look at and talk about than looking at and listening to me. This method can look anywhere between fantastic and just plain kitch. The secret is to not overdo things. I haven't tried to color this material so can't comment on that. Others may know about this..


Good Luck

Old Pete

[Christos]

Thanks for the post fellow wood workers. You have given me some more things to think about.