After you have selected your wood plans, bought the materials and shaped them into what is required for successful completion of your project, you will get to the assembly stage. Any wood plans worth their salt will run you step by step through this area but if you are deciding to go it alone or, using plans that maybe aren’t up to scratch, here are some rough guidelines to help you finish your project.
If you decide to use nothing more than this piece of advice then I am happy – Dry fit all of your joints prior to gluing up! This simply means that you should fit all of your joints into the relevant other piece, IAW your wood plans, prior to using any kind of adhesive. The reason is that it’s the best method of finding any fitting problems that may arise which can then be solved before you have committed yourself to permanently attaching pieces together. As a beginner I made this error and, whilst it can be corrected, the frustration of hammering out a wonky wedged through mortise and tenon joint and damaging the tenon and the leg it was removed from, can easily be avoided by dry fitting and ensuring it is square prior to gluing.
Cramps are invaluable when it comes to assembly of your wood plans, the most commonly used type being the sash or bar cramp. Remember, when utilizing cramps, use wooden blocks between the work and the clamp’s shoes to prevent damaging the work surface. Wherever possible, once you have cramped your piece, check that it is square using a try square or measuring across the diagonals ensuring the measurements are the same on all sides. If your work is not square then an adjustment of the cramps to fully close the joint may be all that is needed, if not, disassemble your piece and check your wood plans cut lengths. Other cramps that you may also use for assembly are:
- G-Cramps – These come in an array of sizes and may have a deep throat for placing pressure away from the edge if needed,
- F-cramps – Quicker to apply than a G-cramp but apply less pressure due to their design,
- Quick-release cramps – As the name implies they are quick to attach and release but apply less pressure due to design. They also have a tendency to slip so may not be useful if the piece will be subject to vibration whilst cramped,
- Band Cramps – Also known as web or ratchet straps, these are particularly useful for curved work,
- Mitre Cramps – Used when cramping mitred corners such as picture frames.
Fasteners such as nails are rarely used except for mould and jig making. Screws on the other hand, are essential for your wood plans and you will find a massive selection available. They come in an array of metals with steel and brass being the most common for woodworking purposes. The most common types of screw heads available are:
- Countersunk Head – Sits flush or just under the timber surface allowing for the screw to be hidden with a filler,
- Round Head – Sits above the surface of the work and becomes a feature of the finished piece,
- Raised Head – A combination of the above two.
The slot types of screws are known as slot and cross-head. Slot screws use a flat-head screwdriver whilst cross-head screws use either Posidriv or Phillips head screwdrivers. You should try to avoid using Posidriv on Phillips screws and vice-verse as the subtle differences can mean damaging the screw and making it’s extraction, if necessary, very difficult. Cross-head screws provide greater grip than slot head and therefore have a lower chance of damaging the screw head.
A couple more suggestions when using screws are:
- For brass screws, first insert an identical steel screw to cut the thread then remove this and insert your brass screw using a non-marking lubricant (Beeswax).
- Always drill pilot holes the width of your screws’ shank prior to inserting the screw. If you are using countersunk heads, countersink the surface with an appropriate sized piece.
- Do not over tighten the screw. A snapped head will leave you with the unenviable task of trying to retrieve the remainder of the screw with whatever metal is left for you to grip.
The final step in your wood plans assembly will be the gluing up. There is a fair range on the market and here is a list of the most common:
- Polyvinyl-Acetate (PVA) – Comes as a white liquid and can be used on joints and will achieve high standards of moisture and mechanical resistance,
- Urea-Formaldehyde (UF) – Comes in powder form requiring water to be mixed before use or as two liquids which are placed on opposing pieces to be joined. Again, high standards of moisture and mechanical resistance,
- Epoxy-Resin – Useful for joining different materials together and is ideal for external work. Not commonly used due to cost and general unsuitability for wood plans,
- Contact Adhesives – Are applied to opposing pieces until tacky and then joined together. Primarily used for applying laminates or when gluing fabrics,
- Cyanoacrylates – Almost instant glues whose thickness determines its curing times. These vary from 5 seconds through to a minute.
Before applying adhesives, ensure you have selected one which fits your wood plan taking into account drying time, moisture resistance and strength required. The normal process of gluing up will involve application of the glue and then cramping until the glue has cured completely. A little tip during this process is to allow the glue which gets squeezed out of the joint during cramping to become rubbery and then remove it with a chisel. This leaves much less residue on your piece than wiping wet glue with a cloth and much less damage than chiseling the fully cured glue.
Hopefully armed with these few tips you can finish up your wood plans with a little more ease.