When making cabinets, having the right clamps is essential for achieving tight joints and keeping everything aligned while the glue dries. Choosing the correct size clamps will ensure you have the right amount of pressure and clamping capacity for the job. In this article, we’ll discuss the common clamp sizes used in cabinetmaking and factors to consider when selecting clamps.
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Quick Answers
- Bar clamps from 12″ to 36″ are useful sizes for assembling cabinet boxes and faces.
- Mini bar clamps in 6″ or 9″ sizes are good for smaller parts like drawers.
- Parallel jaw clamps in 24″ to 60″ sizes help clamp large cabinet carcasses and face frames.
- Consider the thickness of your material when choosing clamp jaw width – usually 1-1/2″ to 3″ capacity is sufficient.
- Apply between 100-150 lbs of pressure for quality glue joints in 3/4″ stock.
Clamp Types and Sizes
There are several common types of clamps used in cabinetmaking, each with sizes better suited to different applications.
Bar Clamps
Bar clamps, also called F-clamps, are extremely versatile for assembling cabinet boxes and face frames. The capacity of the jaw opening determines the size. Common sizes include:
- 12″ bar clamps – Good for smaller parts like drawers.
- 18″ and 24″ bar clamps – Standard sizes for assembling cabinet carcasses.
- 36″ clamps – Useful for larger cabinets and wide face frames.
Longer bar clamps up to 60″ are also available but can be cumbersome for cabinetmaking tasks.
Parallel Jaw Clamps
Parallel jaw clamps have long flat jaws that can apply edge pressure along the full length of a cabinet side panel or face frame. Popular sizes include:
- 24″ parallel clamps – For general cabinet box assembly.
- 36″ and 48″ clamps – For wider cabinets and face frames.
- 60″ clamps – Allows full-length clamping of large carcasses.
The increased clamping surface helps keep joints tight and resist cupping on longer workpieces.
Mini Clamps
Mini clamps with 4-6 inch opening capacities are extremely useful for assembling small parts like drawers. The small size allows clamping in tight spots.
Clamp Jaw Width
Most bar clamps and parallel clamps come in jaw widths from 1-1/2″ to over 3″. Wider jaws allow more glue surface contact and spread clamping pressure over a broader area.
For 3/4″ cabinetmaking stock, clamps with 2-1/2″ wide jaws are a good midpoint. Very wide jaws are unnecessary and can make it tricky to get clamps positioned properly.
Proper Clamping Pressure
Applying adequate pressure is vital for strong glue joints. Insufficient pressure can result in gaps, alignment issues, and weak bonds.
For quality cabinetmaking joints in 3/4″ stock, aim for these guidelines:
- 100-125 lbs for softwoods like pine or poplar.
- 125-150 lbs for hardwoods like oak, maple, or hickory.
Using clamps with integrated pressure gauges takes the guesswork out and makes it easy to apply consistent pressure. For clamps without pressure readouts, you can use a small external gauge to check pressure.
Conclusion
Choosing the proper size clamps for the task is an important consideration in cabinetmaking. Standard bar clamps and parallel jaw clamps in lengths from 12″ to 60″ allow clamping parts of all sizes. Mini clamps come in handy for small parts like drawers. Make sure to use adequate pressure in the 100-150 pound range for quality wood joints. With practice, you’ll gain experience knowing how much clamping force is needed for different situations.
Frequently Asked Questions
What size bar clamps should I buy?
A good starter set of bar clamps for cabinetmaking would include:
- 3-4 small 12″ clamps
- 4-6 medium 18″ or 24″ clamps
- 2 larger 36″ clamps
This provides a range of sizes to handle everything from small parts to large cabinet boxes and face frames.
How many clamps do I need for assembling cabinets?
As a general rule of thumb, plan on having a minimum of 4-6 clamps available for gluing up cabinets and face frames. Longer spans and larger cabinets may require additional clamps. Having 10-12 medium sized bar clamps is a good starting point.
What size parallel clamps should I get?
For cabinetmaking, a set of 24″, 36″, and 48″ parallel clamps will handle most glue-ups. The 24″ clamps work for general cabinet box assembly. 36″ and 48″ sizes allow full-width clamping of countertops and wide face frame sections. Longer 60″ clamps can be useful for very large pieces.
How thick should the jaws be on my bar clamps?
For general cabinetmaking with 3/4″ stock, bar clamps with 2″ or 2-1/2″ wide jaws provide the best balance of capacity versus positioning ability. Narrower 1-1/2″ jaws can potentially dent softer woods. Jaws over 3″ wide are unnecessary and may be difficult to position on smaller parts.
What provides the strongest clamping force for gluing cabinets?
For the strongest and most consistent clamping force, bar clamps or parallel clamps with integrated pressure gauges are ideal. They eliminate guesswork and allow dialing in the optimal 100-150 lbs of pressure. For clamps without pressure readouts, small external digital gauges can be used to check pressure.
Clamping Tips and Techniques
Proper technique is equally important as having the right clamps. Here are some best practices to ensure strong, long-lasting joints:
- Glue both mating surfaces evenly and completely.
- Use cauls and clamping blocks to evenly distribute pressure.
- Tighten clamps gradually in a star pattern to squeeze out excess glue.
- Check for gaps, alignment issues, and sufficient glue squeeze-out.
- Allow glue to fully cure before removing clamps.
- Wipe off excess glue immediately to avoid dried glue marks.
Positioning clamps properly takes practice. Having helping hands can be useful when glue-up requires getting multiple clamps aligned simultaneously.
Clamp Quality and Features
With frequent use, clamps are a worth while investment. Seek out quality brands known for good manufacturing standards.
Key features that improve functionality and ease of use include:
- Integrated pressure gauge – Provides feedback on clamping force.
- Grippy anti-slip pads – Prevent workpieces from shifting.
- Even, padded jaws – Distributes pressure to avoid dents.
- Bar reinforcement – Reduces bar flexing under pressure.
- One-hand operation – Allows tightening without needing to grip clamp bar.
Avoid clamps with sloppy, loose pivots that allow the bar to wiggle. This makes it difficult to maintain proper joint alignment.
Choosing Cabinetmaking Clamps
Here are some top clamp recommendations for cabinetmaking applications:
Best Cabinetmaking Bar Clamps
| Clamp | Sizes | Key Features |
|---|---|---|
| Bessey Tradesman K Body REVO | 12″ to 60″ | Integrated pressure gauge, grippy pads |
| Jorgensen Cabinet Master | 12″ to 36″ | Reinforced bars, wide jaws |
| IRWIN QUICK-GRIP | 6″ to 60″ | Pro-style pistol grip handles |
Best Cabinetmaking Parallel Clamps
| Clamp | Sizes | Key Features |
|---|---|---|
| Jorgensen Parallel Clamp Set | 24″, 36″, 48″ | Heavy duty, anti-slip pads |
| IRWIN QUICK-GRIP Parallel Clamp | 24″ to 72″ | Affordable, deeper 3″ jaws |
| Rockler Parallel Clamp Set | 24″, 36″, 48″, 60″ | Contoured grip handles |
Best Cabinetmaking Mini Clamps
| Clamp | Capacity | Key Features |
|---|---|---|
| Bessey DuoKlamp Set | 1-5/8″ to 4″ | Quick one-hand operation |
| Milescraft 1390 Mini Clamps | 1-1/2″ to 4″ | Value priced set |
| Rockler Mini Clamp Set | 2″ to 5″ | Vinyl coated tips |
The Bottom Line
Having the right assortment of bar clamps, parallel clamps, and mini clamps makes cabinet assembly easier and helps achieve strong, long-lasting joints. Look for quality clamps in a range of sizes to handle all your cabinetmaking needs. Focus on models with features like pressure gauges, reinforced bars, and grippy pads for the best user experience. With practice using proper technique, you’ll be able to efficiently clamp parts in perfect alignment. Investing in good clamps will prove worthwhile as you take on more ambitious cabinetry projects.