Trick to Fill Your Joinery Gaps
{Video} Here’s a quick cheat that will help you when first starting joinery – and an advanced tip to make joints virtually disappear.
After hours of hard work, you find yourself with a small gap (or gaps) in your joinery, making an otherwise sturdy piece look weak.
This small and superficial space somehow gapes at you like an abyss, mocking your skill in joinery. Don’t worry, there are options.
Here is one trick you can use to fix it. However, this won’t make a loose joint any stronger.
The method displayed in the video does work quite well, but you run the risk of the glue and sawdust mixture not accepting stain or varnish and showing up as a light spot once the the stain or varnish has dried. You can check for this prior to the application of a finish by lightly wiping the dried joint with paint thinner/ mineral spirits. This will highlight any glue splotches. If you see splotches, you will have to sand or scrape the joint slightly to remove the excess glue and get back down to bare wood.
An alternative method is to use a small syringe to inject glue into the joint, filling it up to just slightly below the finished surface. Allow the glue to dry thoroughly before proceeding. When you are ready to apply a finish to your piece, dab a small amount of it on the joint and about one to two inches to either side of the joint. Now use a small piece of 220 – 300 grit sandpaper to lightly sand back and forth across the joint.
The fine grit sandpaper will create a small amount of sawdust that will mix with the finish and fill up the joint. The sawdust and finish mixture will dry to the same color as the rest of the finished wood and will virtually disappear. This is also effective for filling in small surface checks or the coarse grain of certain woods like mahogany or oak. This technique is very easy when using oil-based finishes like polyurethane, tung oil and boiled linseed oil. It will also work with water-based finishes and shellac but you will have to work a bit more quickly.
Once the joint is filled, you should go ahead and apply the finish to the rest of the piece to blend everything together.
If you have any other suggestions, let us know in the comments.