How to fix my hatchboard. I broke off one edge.

[Oeanda]

Originally Posted by esarratt

Before I acetone wipe, my hunch is I need to clean up the wood fibers a little bit with some sandpaper?

You can but usually I avoid it. If the jigsaw puzzle will fit together again, that’s the ideal situation and better not to mess with it. So if possible just pick out and remove any loose splinters and broken off bits that are interfering with the fit. At least -that’s the best case scenario. Your break seems pretty clean.
You could use a toothbrush for the acetone.

[stormalong]

Originally Posted by esarratt

Before I acetone wipe, my hunch is I need to clean up the wood fibers a little bit with some sandpaper?

The wood should be clean since it is a fresh break. As long as the two surfaces fit together well don't touch them. Just wipe with lacquer thinner.

I have to disagree with Jedi. Using dowels will make a much stronger fix and reduce the risk of it breaking again. Anytime you see boards edge glued there is some kind of reinforcement. Tongue and groove, biscuits, tenons or dowels. They are there for a reason. Dowels are the easiest to do without special tools. The relatively narrow joint wont stand up to twisting loads. It may break again on the glue joint or right next to it.

[Oeanda]

You can read endless pages of debate among woodworkers re whether biscuits and dowels add any strength. It depends on the specific joint. Often they’re used for alignment purposes and don’t add strength. In a simple edge joint where the grain is all running the same way, they don’t. In the OP’s case where there’s a butt joint, I think they could add some strength against racking, but if using dowels, I’d be more inclined to put through-dowels in from the end rather than fiddling around with a jig for blind dowels, which may do more harm than good. Many ways to skin the cat though.

Also, my ageing eyes can’t really tell from the pics whether your glue joint failed at all, or whether it was just a break in the wood. I was assuming the latter.

[esarratt]

Originally Posted by Oeanda

You could use a toothbrush for the acetone.

Bingo. Thanks!

[esarratt]

Originally Posted by Oeanda

Also, my ageing eyes can’t really tell from the pics whether your glue joint failed at all, or whether it was just a break in the wood. I was assuming the latter.

I understand. I am on readers...for now.


It snapped off the tongue and that part got left in the groove.

[esarratt]

Originally Posted by Oeanda

You can read endless pages of debate among woodworkers re whether biscuits and dowels add any strength. It depends on the specific joint. Often they’re used for alignment purposes and don’t add strength. In a simple edge joint where the grain is all running the same way, they don’t. In the OP’s case where there’s a butt joint, I think they could add some strength against racking, but if using dowels, I’d be more inclined to put through-dowels in from the end rather than fiddling around with a jig for blind dowels, which may do more harm than good. Many ways to skin the cat though.

I have noticed the debate. It is good information.

[Oeanda]

Here’s an article that might be helpful. You can regard your t&g joint as a type of mortise and tenon joint. Should be a fairly straightforward repair. I haven’t had the greatest luck with the cheap doweling jigs. Anyway- Good luck! https://canadianwoodworking.com/tech...a-dowel-joint/

[wsmurdoch]

If after repairing the broken teak board you have doubts about its strength, you will have the perfect excuse to make an identical single board from 3/4" clear acrylic sheet as an alternative to your broken board. A local glass/plastic shop could make it for you or an ebay seller could sell you the base plastic and you could finish it with woodworking tools. I have one that I have made for my boat, and we have used it to give us a view out the back of the boat in bad weather. It has been a good thing.

[s/v Jedi]

These parts are from teak, which is much stronger than soft woods and even stronger than many hard woods.

This is why I recommend epoxy instead of Titebond III. If you glue this with Titebond III then the glue joint may be the weakest part. But this is how all tables etc. are build, with edge grain to edge grain glue joints.

Here we have end grain against edge grain. When you glue this with epoxy, after removing surface oil from the teak with an acetone wipe, then the glue joint will be stronger than the wood.

Of course in that case the wood can still break just next to the glue joint. If you are in doubt -after- gluing, then you can reinforce with a hardwood dowel. Just drill all the way through the small part and an inch or two into the large part, then glue the dowel in, cut flush and give it all a nice coat of teak oil.

Instead of a hardwood dowel, you can also use brass or stainless rod.

I still think it will be plenty strong without reinforcement. The tenon broke where it went into the mortise because of a failed glue joint. You never know what kind of glue they used… hide glue for example. Those joints become weak with age.

[donradcliffe]

Originally Posted by Oeanda

You can but usually I avoid it. If the jigsaw puzzle will fit together again, that’s the ideal situation and better not to mess with it. So if possible just pick out and remove any loose splinters and broken off bits that are interfering with the fit. At least -that’s the best case scenario. Your break seems pretty clean.
You could use a toothbrush for the acetone.

Acetone eats plastic toothbrushes for breakfast.

[esarratt]

I have settled on West System's G/Flex 655-1 (1 oz syringe). That is the smallest quantity of a teak epoxy I can buy. $19.99



I called West's technical support and they said to make sure I mix the epoxy for 1-2 minutes. Sanding both pieces of wood with 80 grit on a Dremel was good. And the best way to mix the epoxy was by weight, not volume. West system's directions say to alcohol wipe, but the tech support guy also said acetone was good.

[s/v Jedi]

Originally Posted by esarratt

I have settled on West System's G/Flex 655-1 (1 oz syringe). That is the smallest quantity of a teak epoxy I can buy. $19.99



I called West's technical support and they said to make sure I mix the epoxy for 1-2 minutes. Sanding both pieces of wood with 80 grit on a Dremel was good. And the best way to mix the epoxy was by weight, not volume. West system's directions say to alcohol wipe, but the tech support guy also said acetone was good.

They must be confused, because it is automatically dispensed in correct ratio from the syringe.

Don’t sand it at the broken tenon if it fits together when test dry fit it. The rest of the surface it’s important to sand to remove the old glue residue down to clean wood.

[esarratt]

Originally Posted by Oeanda

Here’s an article that might be helpful. You can regard your t&g joint as a type of mortise and tenon joint. Should be a fairly straightforward repair. I haven’t had the greatest luck with the cheap doweling jigs. Anyway- Good luck! https://canadianwoodworking.com/tech...a-dowel-joint/

Thanks the article was good.

[esarratt]

Originally Posted by wsmurdoch

If after repairing the broken teak board you have doubts about its strength, you will have the perfect excuse to make an identical single board from 3/4" clear acrylic sheet as an alternative to your broken board. A local glass/plastic shop could make it for you or an ebay seller could sell you the base plastic and you could finish it with woodworking tools. I have one that I have made for my boat, and we have used it to give us a view out the back of the boat in bad weather. It has been a good thing.

I have already been shopping for acrylic long before I broke the hatch board. I had not thought of a glass shop or ebay. The big box stores were expensive. Thanks.

[esarratt]

Originally Posted by donradcliffe

Acetone eats plastic toothbrushes for breakfast.

Good point. I actually melted the inside of my car with some acetone once. I'll use a chip brush.