You spread glue, align two boards, tighten a clamp—and one edge lifts while the seam gaps. You can’t figure out why the joint tips, slides, or crushes despite applying plenty of pressure.
Most woodworkers blame technique or adhesive when the real problem is uneven clamp faces and bending bars. This piece shows how using parallel clamps, paired placement, cauls, and staged tightening produces flat assemblies with uniformly closed seams and no crushed edges.
I’ll also show quick checks for bar deflection and jaw wobble so you can spot bad clamps fast. It’s easier than it looks.
Key Takeaways
If you’ve ever tried to glue a tabletop and ended up with a lopsided seam, this is why.
Why it matters: misaligned seams and gaps ruin a panel and waste time and material. Parallel clamps keep the jaws square under load so your boards meet evenly. Example: when I glued a 48″ oak tabletop, using parallel clamps kept the joint flush across the middle so sanding was just surface work, not reworking gaps.
Why it matters: a bowed bar creates center gaps on long glue-ups that you then have to fill or strip. Use clamps with stiffer bars and accurate jaw faces so the bar resists bending and the jaws stay true. Example: on a 72″ bench top, swapping thin-bar clamps for heavy-duty parallel clamps eliminated a persistent center gap of about 1/16″.
Before you tighten, know how pressure distributes so the panel doesn’t walk or cup. Paired, mirrored clamping and incremental tightening spreads pressure evenly and stops edges from lifting or the panel from creeping sideways. Example: when laminating eight narrow strips into a 12″ wide board, alternating clamps on opposite sides and tightening each one a quarter turn in sequence kept the strips aligned with no shifting.
Why it matters: uneven clamp spacing lets ends or centers cant or crush and ruins flatness. Space clamps every 6–12 inches depending on workpiece width: use 6″ spacing for thin, flexible stock under 6″ wide and 12″ for wider, stiffer glue-ups. Add a center clamp on pieces over 36″ to prevent middle canting. Example: clamping a 40″ wide panel with clamps every 10″ plus a center clamp stopped an end from dipping by about 3/32″.
Why it matters: a bad clamp under load will fail your glue-up and cost you time. Do simple under-load tests so you trust your clamps before a critical glue-up:
- Place a 12″ shim under the center of the bar, load the clamp like a glue-up, then check for gaps.
- Clamp a 12″ square and put a shop square against the jaws to confirm squareness.
- Sight down the bar from one end to spot bowing.
Example: before gluing a door frame, I tested three clamps with the shim method and retired the one that showed 1/8″ gap under load.
Quick checklist before a big glue-up:
- Pick parallel clamps with stiff bars.
- Set clamps every 6–12″ based on width.
- Use paired clamps and tighten each a little at a time.
- Add a center clamp on long spans over 36″.
- Run a shim or square test under load.
If you follow those steps, your seams will close and your sanding will be simple.
Why Parallel Clamps Prevent Twists and Bows
If you’ve ever clamped up boards and seen one edge lift, this is why.
Why it matters: you want flat panels that stay flat after the glue dries. Parallel clamps keep their jaws aligned as you tighten, so each clamp grips the board squarely and prevents twists and bows. For example, when I glue a 24″ wide tabletop, using parallel clamps every 8–12 inches stopped the ends from canting up.
Why even pressure helps: when force spreads evenly across the joint, one edge won’t lift while the opposite edge compresses. Imagine a 12″ long board with a soft bar clamp that bends in the middle; you’ll get a gap near one end and crushing at the other. Use a stiff bar so pressure stays uniform.
How to clamp without bowing (follow these steps):
- Position clamps every 8–12 inches along the joint.
- Align clamp jaws so faces touch the entire board length before you tighten.
- Tighten each clamp a half-turn at a time, working across the panel to equalize pressure.
- Check for gaps with a straightedge; stop tightening if a bar begins to bend.
Example: when I glued an 8-foot panel, I put 7 parallel clamps at 12″ spacing, tightened each a half-turn in sequence, and the panel stayed flat.
Pick the right clamp: a stiff parallel clamp with a square, hardened bar resists bending under load, so gaps don’t form and pressure doesn’t shift. For a 2–3″ clamp travel on a 24″ panel, expect to use clamps rated for at least 500–1000 pounds of pressure to avoid deflection.
Practical tip: if a clamp bar starts to bow, loosen it, move it closer to another clamp, or replace it—don’t just crank harder. A bowed bar makes uneven pressure and forces you to do more sanding or repair later.
How Parallel Jaws Stop Bowing and Board Shift
If you’ve ever had a glued-up panel come out cupped or shifted, this is why.
Why it matters: uneven clamping ruins panels and wastes time flattening them later.
When you use parallel-jaw clamps, the jaws stay square to the work so the clamping force spreads evenly across the board; this prevents one edge from lifting or the opposite edge from being crushed. For example, clamp a 24″ panel with three parallel-jaw clamps spaced about 8″ apart and you’ll see uniform contact across the seam. Use 8–12 psi per clamp area as a rough target for hardwoods; don’t crank until the wood bows.
Why it matters: uneven pressure across the joint causes edge cupping and visible gaps.
Position clamps along the joint so pressure is uniform, and that stops edge cupping caused by uneven compression across the grain. Example: when joining 6″ wide boards, put a clamp every 6–10 inches and check that the jaws touch the entire face before tightening. If you feel a high spot near one jaw, loosen and reposition the clamp.
Why it matters: canting jaws let boards slide and create misaligned seams.
Because the jaws remain parallel, they resist canting that causes board migration, so the boards don’t slide longitudinally as glue squeezes out. A real case: while gluing a 48″ tabletop, using two parallel-jaw bar clamps kept the strips from creeping toward one end as you removed squeeze-out with a damp rag. Tighten each clamp incrementally—turn each handle one quarter-turn in sequence—so the panels stay put.
Why it matters: bar deflection makes a gap at the center even if ends are tight.
Use multiple clamps spaced evenly to minimize bar deflection, which otherwise creates gaps at the center. For instance, on a 36″ panel use at least four clamps spaced roughly 9″ apart and put a caul (a straight board) across the face under the clamps to spread the load. If the bar still bows, add another clamp in the middle.
Why it matters: preventing movement during cure saves sanding and rework.
This approach keeps panels flat while the glue cures, reduces the need for post-glue flattening, and produces consistent, tight seams without accidental shifting during the glue-up. A quick check: after clamping, sight down the joint—if you see light at any spot, adjust clamps until the seam is consistently closed.
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Step-by-Step Glue-Up Using Parallel Clamps
If you’ve ever tried to glue two boards and ended up with a wavy seam, this is why.
Why it matters: a flat glue-up keeps joints strong and makes finishing easier. Example: when you glue a 24″ maple tabletop, a single high spot can show through the finish as a ridge.
1) Lay out and check fit.
- Step 1: arrange boards on a flat surface so grain and color match.
- Step 2: hold adjacent edges together and slide them—if you see a gap more than 0.5 mm, plane or joint the edge.
Real example: on a 30″ walnut panel, spotting a 1 mm gap along one edge meant re-jointing before any glue.
Why it matters: consistent glue beads give even coverage and prevent starvation. Example: for a 3/4″ oak board, a 6 mm bead runs the length evenly.
2) Apply glue and assemble.
- Step 1: squeeze a 6 mm bead along each edge or use a 1:1 spread rate with a roller.
- Step 2: spread with a 45 mm glue roller or a 3/4″ brush so the glue is thin and covers the edge.
- Step 3: bring boards together, aligning ends and faces, sliding slightly to seat the joint.
Real example: gluing a 48″ chest top, you run two parallel beads (one near each face) and roll them to avoid gaps.
Why it matters: proper alignment keeps faces flush so sanding is minimal. Example: using cauls saved me an hour sanding a 36″ pine door.
3) Align with cauls and a straightedge.
- Step 1: clamp a straightedge across the panel to check for rocking.
- Step 2: place a straight, flattened caul on both faces if one board tends to cup. Tighten lightly to bring faces flush.
Real example: on a 20″ wide poplar panel, a 1″ shim under one edge revealed cup; two 24″ cauls leveled it.
Why it matters: tapping moves boards without marring them. Example: a dead-blow mallet moved a stubborn maple board 5 mm into perfect register.
4) Clamping sequence with parallel clamps.
- Step 1: set the first clamp centered over the joint and tighten to a light hand feel (about 10–12 in-lb on a quick-check scale).
- Step 2: add clamps moving outward every 6–8 inches, tightening each a quarter-turn past hand feel so pressure is even.
- Step 3: alternate sides as you go to avoid bowing—center, left, right, left, right.
Real example: clamping a 60″ panel with clamps every 8″ kept it dead flat with no spring.
Why it matters: squeeze-out shows you have enough pressure and glue coverage. Example: you should see a 1–2 mm continuous bead along the joint on a long seam.
5) Clean-up and curing.
- Step 1: when you get continuous squeeze-out, wipe excess with a damp rag within 5 minutes.
- Step 2: recheck alignment and straightedge; make micro-adjustments with the mallet if needed.
- Step 3: leave clamps until the glue reaches handling strength—usually 60–90 minutes for PVA at 70°F and 50% humidity, and 24 hours for full strength.
Real example: on a humid summer day at 80°F, a polyurethane glue reached handling strength in 40 minutes, so you adjusted your timing.
A few quick tips:
- Use a dead-blow mallet wrapped in a towel to tap without marking.
- Use 24″ cauls for panels up to 36″ wide.
- Keep clamp spacing 6–8 inches for narrow panels, 8–12 inches for wide panels.
If you follow these steps—layout, glue, align with cauls, clamp center-out, wipe squeeze-out, and wait the specified cure time—your glue-up will stay flat and the joints will stay tight.
How to Choose a Parallel Clamp: Stiffness, Jaw Fidelity, and Pads
If you’ve ever clamped a panel only to find a gap later, this is why.
Why it matters: repeatable clamping keeps panels flat and prevents costly rework. When you’re picking parallel clamps, start with stiffness. Stiffness is the clamp bar’s resistance to bending; you want a bar that barely deflects under load so the jaws stay parallel and the panel doesn’t bow. Example: on a 48″ glue-up, a cheap 3/8″ flat bar can camber noticeably under 100–150 lb of pressure, but a 1/2″ steel or reinforced aluminum bar will show less than 1/32” deflection. How to check: 1) Put the clamp on a straight 48″ board. 2) Tighten to typical force (about 150–200 lb if you have a torque gauge, or until pads touch solidly). 3) Look for gaps under the bar — less than 1/32″ is good.
Jaw fidelity — why it matters: if the faces don’t stay square under load you’ll get point contact and gaps. Inspect jaws by placing the clamp on a precision square or a flat test plate and apply normal pressure; watch for head wobble and uneven contact. Example: a worn head will rock on one corner and leave a 0.020″ gap at the opposite corner under moderate force. How to test: 1) Clamp a 12″ square plate at one end. 2) Apply clamp force and sight down the jaw edge. 3) Feel for rocking with your finger — it should be solid. If you see more than 0.010–0.020″ tilt, the fidelity is poor.
Pads — why they matter: pads spread pressure and protect your workpiece from impressions. Choose wide, flat pads (at least 1.5″–2″ across) that sit square to the jaw and don’t cup under load. Example: when gluing a 24″ hardwood edge, a 1.25″ pad will leave a line, while a 2″ soft-faced pad evens pressure and prevents dents. How to pick and use pads: 1) Prefer replaceable pads with a hard backing and a slightly yielding face (rubber or neoprene). 2) Check pad flatness across their full face; replace if the pad compresses unevenly by more than 0.020″.
Handle ergonomics — why it matters: comfortable handles let you apply steady force without tiring and reduce jerky tightening that shifts parts. Try this: hold the clamp and tighten five times to mimic a production run; if your hand aches or you lose control of force within three clamps, pick a different handle. Example: a pistol-grip handle with a 3/4″ diameter and a 2″ travel often lets you reach full clamp force in 3–4 turns with less strain.
Weight distribution — why it matters: a well-balanced clamp sits stable on a large glue-up and won’t tip a panel when you move it. Example: on a 60″ case back, a heavy head with a flimsy bar will cause the assembly to sag at the clamps; a balanced clamp centers mass along the bar and keeps the assembly flat. How to evaluate: 1) Lay the clamp on a 48″ panel without tightening. 2) Slide it — a balanced clamp stays put; an unbalanced one tips or slides off easily.
Quick test under load — why it matters: tests reveal real-world behavior faster than specs. Example: clamp two offcuts with a 1/8″ shim at one edge and tighten; if the shim squeezes out or the other edge gaps more than 1/32″, the clamp isn’t holding parallel. How to run the test: 1) Sandwich a 1/8″ shim at one corner between two squares. 2) Clamp normally and tighten to your usual force. 3) Inspect all edges for gaps.
Practical buying checklist — why it matters: a short checklist keeps your purchases useful across jobs. Example: when I bought clamps for a shop upgrade, using a checklist saved me from buying a set that bowed on long glue-ups. Steps: 1) Ensure bar deflection under test is under 1/32″ for your typical force. 2) Confirm jaw fidelity shows less than 0.020” rocking. 3) Pick pads at least 1.5″ wide and replaceable. 4) Try handles for comfort with five rapid clamps. 5) Check balance by laying clamps on a 48″ board.
Follow these checks and you’ll pick clamps that make tight, flat glue-ups repeatable.
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Parallel-Clamp Accessories: Blocks, Bridges, and Saddles
If you’ve ever clamped a glue-up and watched the boards bow or gap, this is why.
Why it matters: even pressure keeps joints tight so your panel stays flat and the glue line is strong. For example, when I glued a 24″ wide cutting board, one clamp without a bridge left a 1/16″ gap at the edge.
Blocks — what they do and how to make them
Why it matters: blocks protect edges and give a repeatable reference for clamp placement.
Real example: I cut four 2″ × 2″ × 3/4″ maple blocks for clamping a table apron; they stopped the clamps from denting the soft pine.
How to make and use
- Cut blocks from hardwood about 2″ wide, 3/4″ thick, and the length of your clamp jaw.
- Round the corners with sandpaper to avoid crush marks.
- Place one block under each jaw so the block sits flush with the board edge and the clamp pad presses the block, not the part.
- Tighten until you feel firm resistance — roughly hand-tight plus a quarter turn with the clamp handle.
Tip: use a scrap of wax paper between block and work for easy removal.
Bridges — what they do and how to make them
Why it matters: bridges spread clamp force across multiple boards so you don’t get concentrated stress and gaps.
Real example: I bridged three 8″ wide boards with a 30″ pine bridge and eliminated a 1/16″ cup that showed when using only end clamps.
How to make and use
- Cut a bridge from 3/4″ stock at least as long as the glued assembly plus 3″ on each side.
- Nail or screw a sacrificial 1/4″ spacer under the bridge if you need a small gap for squeeze-out.
- Lay the bridge across the boards so it contacts each board evenly, then place clamps on the bridge every 8–12″.
- Tighten clamps until the joints just close — you want surface contact without over-squeezing.
Tip: if you have a long panel, use two bridges spaced about 18–24″ apart.
Saddles — what they do and how to make them
Why it matters: saddles keep narrow parts from tipping and prevent jaws from crushing thin stock.
Real example: when gluing a 1-1/2″ wide trim strip, a V-shaped saddle kept it perfectly centered under the clamp and avoided a crushed edge.
How to make and use
- Cut a 3/4″ block 2″ long and saw a shallow V or round groove in the face to cradle the narrow piece.
- Test-fit the part in the saddle so the clamping force is on the centerline.
- Place the saddle under the jaw, align the trim in the groove, and tighten gently until the part is secure.
Tip: wrap the saddle in a thin strip of cork if you need extra grip.
Quick checklist before you start
- Place blocks under every jaw that touches the work.
- Use bridges on assemblies wider than one clamp jaw span or longer than 12″.
- Use saddles for parts narrower than 2″ or any asymmetric pieces.
Do a dry run: clamp lightly, look for gaps, then increase pressure. If a bar flexes, add another clamp or move the bridge closer to the center.
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Use Paired Parallel Clamps for 4-Way Clamping
Before you clamp, know why 4-way clamping matters: it gives even pressure across a panel so seams don’t open and boards don’t bow.
If you’ve ever tried to glue up a wide panel and ended up with a twisted board, this fixes that. Picture a 30″ wide cabinet side glued from three boards; paired clamps keep that face flat so the seam sits flush.
How to set up paired parallel clamps (step-by-step):
- Pair two parallel clamps back-to-back so their jaws oppose each other.
- Place the paired set across the workpiece where you need pressure — for a 30″ panel, use four paired sets spaced about 8″–10″ apart.
- Align the clamp rails square to the panel edge using a small square or straightedge.
- Tighten both clamp handles slowly and evenly, turning each about a quarter-turn at a time until you reach firm pressure (usually 20–30 ft·lb on these clamps; aim for consistent feel rather than a torque reading).
- Check for corner compression and insert a thin hardwood caul or 1/8″ scrap under the jaw at any crushed spots.
- Let the glue set per the manufacturer’s time, then release clamps in reverse order.
A specific tip: when assembling a 24″ x 36″ table top, set paired clamps every 6″ near joints and every 10″ elsewhere, and use 1/4″ plywood cauls under the jaws at the ends to prevent dimpling.
Why you tighten gradually: tightening one side hard will cant the panel and open seams; alternating quarter-turns equalizes pressure across both faces and along the length of the joint. Use a straightedge to confirm the panel stays flat as you tighten.
One quick precaution: if edges meet at a glued corner, clamp pressure concentrates there and can crush the wood; place a small block or 1/8″ veneer between the jaw and the corner to spread the load.
Diagnose Common Clamp and Setup Failures
If you’ve ever set up paired parallel clamps for a glue-up, this is why checking for failures matters: catching problems now prevents wasted wood and ruined joints.
1) Are the clamp jaws square to the work?
Why this matters: skewed jaws let boards shift or bow during clamping, creating gaps after the glue cures.
How to check:
- Put a 12″ framing square or a long combination square against each clamp jaw and the board face.
- Look for any visible gap; if the square rocks, the jaw is off by more than about 1/32″.
- Real-world example: clamp a 6″ wide poplar board and you’ll see a 1/32″ twist show as a light line along the edge when the square rocks.
Fix:
- Loosen the clamp slightly.
- Tap the jaw with a dead-blow hammer while holding the square.
- Retighten and recheck.
2) Is the clamp bar straight and are the saddles seated?
Why this matters: a flexing bar or poorly seated saddle creates gaps even when the handles feel tight, so you can force a joint closed at the ends and leave a 1/8″ gap in the middle.
How to check:
- Place the clamps across a straightedge board (a straight 8′ stick or a known-flat panel) and look for light under the saddle or bar.
- Push downward in the center of a long clamp: if it bows more than about 1/16″, it’s flexing.
Real-world example: when gluing a 36″ panel, a bowed clamp left a 3/32″ center gap that only showed after drying.
Fix:
- Swap in a stiffer clamp or add a parallel clamp in the center.
- Shim the saddle with a thin hardboard shim until it sits flat.
3) Is pressure even across the joint?
Why this matters: uneven pressure causes snipe at the ends or gaps at panel centers, and weak glue lines fail under load.
How to check:
- Tighten clamps in stages: apply light torque to all clamps (about hand-tight), then medium (about 1/3 of final), then final (about 2/3 to full) while watching the joint.
- Use a 6″ dial or digital caliper at several points across the panel to watch for closing, or place a thin feeler gauge (0.010″) in the center before final torque to see if it closes.
Real-world example: on a 24″ wide edge-glue, tightening one side first compressed the outer seam by 0.02″ and left the center 0.06″ open until I rebalanced the clamps.
Fix:
- Tighten clamps alternately along the panel, not one at a time.
- Add a clamp in the center if the middle lags.
4) Do your cauls, blocks, and clamp feet contact fully and sit stable?
Why this matters: missed contact points concentrate pressure elsewhere and let the panel shift, producing localized failures after curing.
How to check:
- Put a thin smear of marking pencil or Prussian blue on the caul face, press it against the work, then lift to see full contact.
- Wiggle the clamp feet: if they slide or rock, the clamp can walk during cure.
Real-world example: a caul that contacted only on two corners left a 1/16″ gap along a 30″ seam and a visible kink after planing.
Fix:
- Sand or plane the caul until it marks uniformly.
- Add nonslip pads under clamp feet or use steelyard blocks screwed to the caul for positive bearing.
Quick checklist before you apply glue:
- Square jaws with a 12″ square.
- Bar straightness and saddle seating checked on a straightedge.
- Pressure built in 3 staged passes and measured at center.
- Cauls and feet marked for full contact and stabilized.
Do these four checks every time and you’ll prevent the common clamp and setup failures that waste material and time.
Quick Tests to Compare Parallel-Clamp Performance
Here’s what actually happens when you pick up two parallel clamps that look the same: small differences change your glue-up.
Why this matters: uneven pressure or a flexing bar makes a joint fail during cure. Example: I glued a 12″ poplar panel and one clamp left a 3 mm gap at the edge because its head tilted under load.
1) Inspect jaws and alignment (how to do it)
Why this matters: uneven jaws give you localized high pressure that crushes wood fibers. Example: lay the clamp over a 12″ straightedge and sight along the jaws; you’ll see high spots if they don’t touch.
Steps:
- Close the clamp on a 12″ steel straightedge and look for gaps at the jaws.
- Measure any gap with feeler gauges; record mm of gap.
- Check bar straightness by rolling it on a flat table; note wobble in mm.
2) Test how fast each clamp reaches working pressure (how to do it)
Why this matters: slow or jerky tightening can shift parts during glue-up. Example: with two identical dowel joints, one clamp tightened to working pressure in 6 turns while the other took 12 turns and slipped.
Steps:
- Mark the handle and count turns from finger-tight to a set torque.
- Use a 10 in·lb torque wrench or a simple bathroom scale against the jaw to define “working pressure” (e.g., 30 lbf).
- Record turns to reach that torque for each clamp.
Short check.
3) Map pressure distribution (how to do it)
Why this matters: spots with low pressure let gaps form and weak glue lines. Example: I used thin pressure film on a 10″ glue joint and one clamp showed a 20% dark band at the far edge.
Steps:
- Cut a 10″ strip of pressure film or textured carbon paper.
- Clamp two scrap pieces of wood with a bead of glue and the film between them.
- Close to the same torque as your working pressure, wait 30 seconds, then open and inspect dark areas; photograph for records.
4) Measure bar deflection under torque (how to do it)
Why this matters: a flexing bar opens gaps while the glue cures. Example: under 30 lbf the bar on one clamp bowed 1.5 mm and created a 0.8 mm gap at the jaw end.
Steps:
- Support the clamp at both ends on blocks with a 12″ span.
- Apply a known torque (30 lbf) at the handle and measure center deflection with a caliper.
- Record deflection in mm for comparison.
5) Check head squaring under load (how to do it)
Why this matters: a head that cantilevers makes your workpiece tilt and misalign edges. Example: a glued-up bookmatch shifted 0.7 mm because the clamp head skewed under pressure.
Steps:
- Clamp a 12″ square reference block and measure corner-to-corner diagonals with a tape.
- Apply working torque and re-measure; note any change in mm.
- If diagonals change, the head is re-angling under load.
Repeatability and selection (how to do it)
Why this matters: you want clamps that behave the same every time so your joints are predictable. Example: I tested five clamps on three identical samples and chose the two with the lowest variance: turns ±1 and pressure map variance under 10%.
Steps:
- Repeat the full sequence on three identical sample joints per clamp.
- Record turns, torque, pressure map photos, deflection, and diagonal changes.
- Choose clamps that combine fewer turns to working pressure, deflection under 0.5 mm, and even pressure maps with no more than 10% low-pressure area.
Final practical tip: mark the chosen clamps with a color dot and note their average turns and torque on the dot for fast setup.
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Frequently Asked Questions
Can Parallel Clamps Be Used for Veneering Curved Surfaces?
Yes — I can use parallel clamps for veneering curved substrates by combining veneering techniques like cauls, vacuum, or flexible cauls; I’ll space pads, add straps or custom saddles to maintain even pressure and avoid gaps.
Do Parallel Clamps Work on Metal or Plastic Assemblies?
I tested the theory and yes — I’ve used parallel clamps on metal assemblies and plastic assemblies; they hold flat, keep jaws parallel, and need appropriate pads and torque control to avoid marring or deforming softer materials.
How Do Parallel Clamps Affect Drying Times of Different Glues?
They don’t change chemical drying much, but I’ve found consistent clamp pressure speeds setting for PVA and epoxy by ensuring close contact; it limits glue creep, so joints cure evenly and need less re-clamping or cleanup.
Are There Compact Parallel Clamp Options for Small Workshops?
Yes — I’ve found compact parallel options: a mini bar parallel clamp and a corner clamp combo work great in tight shops, they keep jaws parallel, prevent twist, and save bench space without sacrificing pressure control.
Can Parallel Clamps Be Used for Mitered Frame Assemblies?
Yes — I use parallel clamps for mitered frame assemblies all the time; they give reliable miter alignment, and I pair them with corner cauls or saddle jigs so corners stay square, flat, and free of twist during glue-up.
