In an otherwise attractive piece of wood, an unsightly split or crack can run deep like family turmoil. Most wood fillers are intended to be little more than aesthetic solutions. Even the hardiest fillers are intended to withstand compressive forces but not sheer stress. Here I will demonstrate my solution for when I don't want to give-up on a piece of wood. This block was salvaged from a eucalyptus tree that fell on my grandmother's house (don't worry, I'm fine). I want to be able to work on it without risk of further splittage.
I do all my wood repair at TechShop.
I do all my wood repair at TechShop.
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I have found polyester resin to the be ideal for this kind of repair. It is very strong in it's cured state, it seeps into fibers and produces a strong bond (it's intended use is laminating wood and resining fiberglass) and it is slightly flexible, so it will move with wood as it bends and expands with humidity.
*Not pictured: the necessary plastic bag
*Not pictured: the necessary plastic bag
![[Video] Mixing Polyester Resin](http://cdn.instructables.com/FO5/CP3K/WDFEZ7BGP9V/FO5CP3KWDFEZ7BGP9V.SQUARE.jpg)
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did you trim off a the top (most gnarly) layer of resin with a band saw to skim off the top layer or polyester resin, taking a small amount of wood off as well followed by plane/sanding?
the resin looks like tough stuff and would really dull down a hand plane -- plus you say it turns into glass like shards when hit with a chisel.
After you've taped off the ends to keep the resin from running out, clamp the split wood with C-clamps or a vice. Use backing boards if needed to avoid leaving marks. Your goal, if possible, is to force the splits closed, but if not, you should be able to squeeze them tighter together at least a little.
Then pour the resin on the break fault lines. Finally, remove the clamps. The vacuum created by the crack gap expanding back to its original shape will suck the glue in, deeper and faster than if you relied on gravity alone.
If necessary, add more resin after removing the clamps. The deep-penetration work has already been done, and the larger gaps that remain are easier to fill anyway.
In order to achieve the suction, the crack must be entirely covered on its entire length: either by tape (no gaps!), or resin. If there's a hole - say, if the crack goes through to the back side of the wood, but you haven't covered it with glue there - air will flow in much easier than resin.
It's OK to cover a two-sided crack on both sides. This isn't a delicate operation, and you can work quickly to try to get the clamps off before the resin on the bottom side drips off.
You might consider epoxy too (more expensive, easier to mix, stronger and less toxic). To use less resin you might consider to had some woodcell (or other microballoons). It will cost less in resin and be better mechanically. Anyway it will become less fluid so adjust to your needs.
Other than, for pooring resion consider wearing mask with ABEK1 filters. And you workout your result use P1 or P2 dust filters. I know two people that suffered huge pulmonary issue, really it is not a joke.
To fix the crack in mine, (also the stock on my 22 rifle), I used Gorilla Glue.
I used the light for the "stringer," and the dark on the rifle stock.
Worked great and have had no problems.
PS; That was way over 2 years ago
Scotttland - This is a GREAT instructable !!!
Very nice pictures, nice and clear and i know hardwood is quite expensive around my area's and if i get hold of some discounted hardwood thats only cheaper because its got these types of cracks in it, Your PERFECTLY RIGHT - why discard it or destroy it when we can RE-PURPOSE and RE-CLAIM it to better suit our needs, not totally slamming the 'Go-Green' attitude as we will eventually run out of natural resources, but whilst they are still around, its better to recycle & re-purpose as much as we can nowadays !
Once again, a Darn-Great-Job on bringing this repair-idea into the light !
Even looks aesthetically pleasing to the eyes by using the Dye ! (so many colours, so many possibilities have now opened up !!!) NOW i want these cracked timbers just to make my finished work-pieces look artistic & unique !!! Really happy with this idea, made my day !
Just one question though, is the dye needing to be oil-based, to better mix with the resin ?
Sounds like it should be oil-based but just to make sure, what was the dye you used ?!?
Also many thanks in advance for the confirmation of the Dye you used !!!
Keep up the great work !!!
http://www.rudefurnishings.com/
Thanks.
Cracked wood is cracked wood : you will never make one piece of new wood from two pieces !â¦
resin is fine for small cracks or â¦Â as glue ! But not with the purpose of making one piece of wood out of two.
All woodworkers I know (some being very fine at their craft) will find how to use the cracked piece of wood shown, generally by using it for two or three different pieces ⦠if they need to work the whole mass they'll pick a other piece from their stock.
What kind of job does one expect to get from a piece of material that will show a 5 or 10mm gap filled with resin ???⦠Doesn't make any sense ⦠except for amateurish work.
Not to talk about health and environmental issues.
No reason to shout.
Maybe I was a little edgy yesterday.
If so please forgive me for that.
Still I don't think that my remark should be be dismissed because you think it goes against "progress".
I didn't state I was against resin altogether : as a matter of fact I built my own 30 ft sailboat using plywood and epoxy.
Still I do not think this idea is a great one : it may be practical in a few limited cases, but two pieces of wood will never make one. One of the reason is purely technical : although modern resins are mighty strong, both material (wood + resin) do not have the same elasticity : wood will break before the resin but it will break somewhere else because the two parts (wood / resin) have not the same resiliency rate.
Also if you try to machine a piece of wood filled with resin you will have to replace your blades much more frequently : cost is a factor too.
Then again the environmental and health issue are important. A short visit to one of these companies that use epoxy and other resins by the ton are quite instructive : these places are as spotless as a NASA assembly plant or a surgery room. That is for 2 reasons why : 1) health and environmental issues 2) some resins require a highly controlled environment, otherwise their chemical reaction will not perform as to the book. 12 years ago we had the case with a neighbor company here (France â¦Â I know, I know â¦Â those French ;) : a 5 days production (boat hulls) had to be dumped because of air pollution from the local refinery reacted with the resin : it never happened before. Still it happened at that time. They had to redesign the whole ventilation system to avoid any new mishap.
Moral : use resin sparingly. Because it is a health and environmental hazard, and as an individual consumer you cannot control the quality of the result although it will certainly be good enough in 99% of cases. Use it wisely too as resin will never make one piece out of two. Unlike welding it is design to bound â¦Â not to make two pieces structurally one.
This being said, I do have on an almost permanent basis half a kilo of epoxy resin in my workshop. Strangely enough : the more I became familiar with it the less I use it. Other glues / "resins" are as effective although somewhat more "old fashion".
Sorry again for being too abrupt in my 1st response.