Level Finish · Technical Test Report

Alpha P180 vs 3M Cubitron II: two controlled tests, published in full

Level Finish Alpha P180 disc vs 3M™ Cubitron™ II P180. Two separate controlled tests on body filler, reported side by side and never combined. Test 1 is a controlled follow-up that continued directly from a confirmed P80 endpoint, one minute per product. Test 2 is the P180 stage of a continuous body-filler sequence, where the same panels were progressed from P80 through P320. The panels and starting conditions differ, so each test stands on its own numbers. One pattern repeats in both: Alpha recorded the higher removal. The finish result does not repeat: Alpha finished lower in Test 1, 3M finished lower in Test 2. Both facts are published here.

The P180 post image, as published on our Facebook and Instagram on October 27, 2026: machine sanding with vacuum extraction, the way this test was run.

What happened, in short

• Test 1, controlled follow-up, one-minute trials: Alpha removed at 1.0922 mil/min vs 0.8112 mil/min for 3M Cubitron II, 34.6% higher. Alpha also finished finer: average Ra 3.688 µm vs 3.863 µm, with the larger Ra reduction from the starting surface (0.690 µm vs 0.319 µm).
• Test 2, continuous sequence stage, 60-second trials: Alpha recorded 28.258 mil of matched removal vs 16.106 mil for 3M, 75.4% higher. On finish, 3M recorded the lower final average Ra: 3.582 µm vs 4.039 µm, with the stronger matched Ra reduction.
• The honest summary: Alpha led removal in both tests. The finish verdict flips between the two trials, and 3M also took the removal-consistency category in Test 1. This page publishes all of it.

Test 1: controlled follow-up from the P80 endpoint

Method. This test continued from the confirmed P80 endpoint of the P80 follow-up comparison, so each P180 trial started on the surface its own P80 stage had produced. Each product sanded its body-filler panel for exactly 1 minute. Removal was measured at 132 coordinate-matched depth locations per panel and calculated coordinate by coordinate (starting depth minus post-test depth); negative coordinate changes were retained in the analysis rather than set to zero. Surface roughness was recorded at 22 Ra locations per panel. Full-disc before and after photography and microscopy at 500X and 1000X documented disc condition. The panels did not begin at identical averages (starting average depth 25.3173 mils for 3M, 25.8242 mils for Alpha; starting average Ra 4.182 µm for 3M, 4.378 µm for Alpha), which is why removal is computed per matched coordinate instead of by comparing endpoint averages.

Test 1: material removal (1 minute)	3M Cubitron II P180	Level Finish Alpha P180
Starting average depth	25.3173 mils	25.8242 mils
Post-test average depth	24.5061 mils	24.7320 mils
Average removal, and removal rate	0.8112 mil/min	1.0922 mil/min
Median removal	0.6000 mil	1.0000 mil
Removal standard deviation	0.7093 mil	0.9743 mil
Maximum single-coordinate removal	3.9800 mils	5.5400 mils
Coordinates with positive removal	130 of 132	121 of 132

Alpha's average removal rate was 34.6% higher. Cubitron II's removal was the more consistent distribution: lower standard deviation, positive removal at more coordinates, and fewer negative coordinate changes (1 vs 10), which the report treats as measurement or coordinate-placement variability.

Average removal rate (mil/min), Test 1.

Test 1: surface roughness (Ra)	3M Cubitron II P180	Level Finish Alpha P180
Starting average Ra	4.182 µm	4.378 µm
Post-test average Ra	3.863 µm	3.688 µm
Post-test median Ra	3.818 µm	3.700 µm
Post-test Ra standard deviation	0.462 µm	0.436 µm
Post-test Ra range	1.732 µm	1.483 µm
Average Ra reduction	0.319 µm (7.6%)	0.690 µm (15.8%)

Alpha finished 0.175 µm lower in average Ra while removing more stock in the same minute, and its post-test Ra readings grouped slightly tighter. Note the starting surfaces: Alpha began this stage on the rougher P80 surface (4.378 µm vs 4.182 µm), and both baselines are shown above rather than hidden.

Test 1: disc condition and microscopy

Both discs remained physically intact after the one-minute trial. Visible particulate accumulation was localized and nonuniform on both products, the hole patterns remained readily identifiable, and microscopy continued to show identifiable surface structure on both, with no continuous deposited layer obscuring either surface. No quantitative wear, loading, or remaining-life percentage was established for either product, and none is claimed.

Test 1: performance index

The follow-up report scores this test with a weighted index. The weights and formulas are disclosed in full: removal rate 33.33%, final Ra 27.78%, Ra refinement 16.67%, Ra consistency 11.11%, physical integrity 11.11%, with the leading result in each scored category set at 10. Loading was documented qualitatively and excluded from the score.

Category	Cubitron II	Alpha
Removal rate	7.43	10.00
Final Ra	9.55	10.00
Ra refinement	4.62	10.00
Ra consistency	9.44	10.00
Physical integrity	10.00	10.00
Weighted P180 Test Performance Index	8.06	10.00

These are Level Finish relative index scores derived from this test only, with the leader set at 10. They are not third-party certification scores and should not be compared across unrelated tests.

Test 2: the P180 stage of the continuous sequence

Method. In the second test, the same body-filler panels (3M Bondo Fast Dry) were progressed through a continuous sequence, P80, then P180, then P220, then P320, with each stage starting from the surface the preceding stage created. Sanding used an Indasa 5 mm dual-action orbital sander with vacuum extraction. The P180 stage ran 60 seconds per product and was measured by coordinate-matched removal and final Ra.

Test 2: P180 stage results (60 seconds)	3M Cubitron II P180	Level Finish Alpha P180
Matched material removal	16.106 mils	28.258 mils
Final average Ra	3.582 µm	4.039 µm
Ra standard deviation	0.505 µm	0.710 µm
Matched-average Ra reduction	35.6%	6.5%

Test 2 finding: Alpha led removal by 75.4%. Cubitron II took the finish categories in this trial, with the lower final average Ra and the stronger matched Ra reduction. The sequence continued to P220 and P320 on the same panels; those stages are separate results and will be reported on their own.

How to read these two tests

The absolute removal numbers differ sharply between the tests because the starting points differ. Test 1 panels began at a finished P80 endpoint with most shaping already done, so one minute of P180 refinement removed about a mil. Test 2 panels carried full filler stock into the stage. The numbers are not comparable across the two tests, and they are never averaged or combined here. What repeats across both sets of conditions is Alpha's removal lead. What does not repeat is the finish outcome: Alpha finished finer in the follow-up trial, Cubitron II finished finer in the sequence trial. P180 is a refinement stage, where removal and finish both matter, and which result matters more depends on the panel in front of the technician. That call belongs to the technician. Our job is to publish the measurements exactly as recorded and let you decide for yourself.

More test results

Alpha P80 vs 3M Cubitron II, two controlled tests: see the P80 test results. Omega P1500 vs 3M Purple 260L: see the P1500 test results. Omega P2000 vs 3M Purple P2000, filmed side by side on one panel: see the filmed test results. More reports are filed here as testing is completed.

Notes and limitations

Each test is a single controlled trial under its documented conditions, and the results describe those trials. Test 1 retained negative coordinate changes in its analysis and treats them as measurement or coordinate-placement variability. Photographic and microscopic evidence is qualitative. Index scores are Level Finish relative scores for the stated test only, weighted as disclosed, and are not third-party certification. Results from one grit or substrate do not transfer to another.

Frequently asked questions

Which P180 disc removed more material?

Alpha, in both tests. In the follow-up trial Alpha's removal rate was 1.0922 mil/min vs 0.8112 mil/min for Cubitron II, 34.6% higher. In the sequence test Alpha recorded 28.258 mils of matched removal vs 16.106 mils, 75.4% higher.

Which P180 disc left the finer surface?

It depends on the test, and we publish both. In the follow-up trial, Alpha finished lower: 3.688 µm vs 3.863 µm average Ra. In the sequence test, Cubitron II finished lower: 3.582 µm vs 4.039 µm.

Why are there two P180 tests with such different removal numbers?

Different panels and starting conditions. Test 1 continued from a finished P80 surface, so a one-minute refinement pass removed about a mil. Test 2 panels carried full filler stock into the P180 stage. Each test's internal comparison is the result; the absolute values do not transfer between tests.

Did 3M win any category?

Yes. In Test 1, Cubitron II's removal distribution was more consistent (lower standard deviation, positive removal at 130 of 132 coordinates vs 121). In Test 2, Cubitron II recorded the lower final average Ra and the stronger matched Ra reduction.

Level Finish · St. George, Utah · level-finish.com · Sources: Level Finish Controlled P180 Abrasive Follow-Up Comparison and Coarse-to-Medium Grit Body Filler Analysis, P180 stage. Page prepared November 13, 2026. All numbers transcribed exactly from those reports; no values added or altered.