2 July, 2012 3 Comments
A reader requested I give details on how I did the DIY mitre join on my IKEA Pragel benchtop:
Warning: this was tricky, do at your own risk. Ask for clarification if you need it, I wrote it quickly and from years-old memory, but if enough people want it I can add more info. If it’s difficult, or you ruin your benchtop, don’t blame me for trying to help you.
- Carefully mark a 1cm x 1cm square for the diagonal cut (pencil on masking tape)
- Cut the “male” piece, to the correct length (keeping an 1cm for the join!) with a $50 Ozito circular saw (upside down for a neater cut as saw cuts from the bottom, masking tape along cut on the top (now the bottom – where saw enters). |‾‾‾‾‾‾‾|
- Draw a pencil line joining corners of the 1cm square and cut it with a hand saw (new blade is best). |/‾‾‾‾‾‾‾|
- For female piece, cut the 1cm square diagonal first very carefully with hand saw. _/_______|
- On the bit to be removed, go 5cm along from that cut (in step 4) and carefully cut 1cm in. _/_|______|
- Circular-saw the 1cm thin cut-out piece from the edge to that cut (in step 5). (Actually I used a router, but the cheap circular saw cut cleaner and straighter). _/_|‾‾‾‾‾
- Use the handsaw again for the last 5cm from the step 5 cut to the step 4 diagonal cut. _/‾‾‾‾‾‾‾
- Hopefully (!) they fit together nicely now.
- Get 2 benchtop joining bolts from the kitchen section at Bunnings (you must see that 5$ bunnings flatpax DVD that shows how these work to understand the next steps).
- Mark 4 holes on the bottom, 2 each on each bench piece, about 8cm from the join edges (not sure it’s 8, check this with the bolts, circle edge should end up 1-2cm from join edge) and about 30% of the way along the edge so they are evenly spaced from each other and the edges.
- Use the biggest wood spade from Bunnings (32? 35?) to drill wide holes – only 1-2cm or so deep – for the “C” part of the benchtop fasteners.
- Drill/saw/route a hole for the bolt part of the bolts, from those holes to the join edges, so the bolts will work as you’ve seen in the video
- In the video, they say biscuit join for strength; I didn’t actually need to, just carefully matched heights of benchtop pieces and supported both from below near join
- Put it all in place for a “dry run” (semi-tight bolts but no glue) to see if any adjustment needed.
- Glue a line of glue (good wood glue or MRMDF glue – I used araldite but wouldn’t recommend, it dried super fast in my hot kitchen window sun, and I almost couldn’t tighten bolts in time!) along the middle of the join, and a small line of silicon along near the top of the join.
- Put together in place in kitchen, make sure it’s all perfectly level and tighten the bolts.
- Some silicon should squeeze out the top. Make sure the whole join is covered by silicon so no moisture gets in the top.
- Spray some spray’n’wipe over the silicone so it doesn’t stick to the benchtop itself (just the join) when you wipe the silicon off
- Wipe the excess silicon off with your finger (pausing to wipe finger with something as needed). Check glue bottle for drying times.
Note: don’t forget to waterproof the underside of Pragel benchtops if near wet (sink, dishwasher, oven or cooktop) as said in Pragel’s instructions.