The advantages with the H join or splined join are:
- the whole standard panel width/length can be used
- absolutely fair if done correctly,
- the peel ply can be left on, and
- a larger area of laminate in contact.
The disadvantages are using more duflex (off cuts) and the join is stiffer, more rigid than the rest of the panel unlike a Z join.
The join is prepared using standard router bits so the joint is fair like a factory cut Z join. I joined three pieces of marked and cut 16mm Duflex with 2 splines of 13mm Duflex made from long 13mm off-cuts. These joins made up one of the two forward deck panels.
Below – Three parts of the panel rebated and splines cut, only peel ply on the splines to be removed and little hand sand to ensure no glue bumps or loose material remain in the joins.
Below – Close up.
Below – The prepared edges of the join
Below – Dry fit
Below – Dry fit up close.
Below – All parts and tools ready to start on two joins in our twenty minute glue working time.
Below – Glue applied to all surfaces of the spline which has been inserted into the rebated edge of the clamped down centre part.
Below – Glue applied inside the rebated edge.
Below – The parts were fitted together, slid, pushed, and then given a quick scrape clean of the oozed excess glue…..
Below – Plastic wrapped boards were placed, ratchet straps wrapped, jacks fitted lightly with timber spacers, the straps tightened and then the jack pressure firmed up. A high set house or shed with serious over heads is required.
Note: A Z-Press (if there just happened to be one in the tool kit) would save a lot of mucking about here.
Of course the screw together technique used on z joins works well but irritates me because the rows of holes need repairing.
Below – Completed H join.
Below – Close up of joint complete with lens shadow.
The Scrumble Project 