Harris 1100 Aluminum TIG GTAW Welding Rod (AWS A5.10 classification ER1100) is a commercially pure aluminum filler metal containing a minimum of 99.0% aluminum. It is specifically designed for gas tungsten arc welding (GTAW/TIG) of 1100 and 3003 series aluminum base metals. The 1100 alloy is renowned for its exceptional ductility, outstanding corrosion resistance, and high electrical conductivity, making it a preferred choice when the weld joint must match the mechanical and chemical properties of pure aluminum components. Welders working on food-processing equipment, chemical tanks, architectural panels, and electrical conductors consistently turn to ER1100 rod because the finished bead remains soft enough to be formed without cracking, and the weld's surface finish is smooth enough to accept post-weld anodizing without blush lines or discoloration.
The Harris 1100 rod ships in a 10-pound box of 36-inch cut lengths in multiple diameters. Flat, straight rods feed consistently into the TIG arc without the erratic dipping that can occur with bent or warped filler metal, protecting both the tungsten electrode and the molten puddle from contamination. Harris Products Group, a Lincoln Electric company, maintains tight tolerances on alloy chemistry to ensure every lot meets or exceeds AWS A5.10/A5.10M specification.
The Harris 1100 aluminum TIG rod carries the following classification and typical mechanical data:
- AWS Classification: ER1100 per AWS A5.10/A5.10M
- Aluminum Content: 99.0% minimum (commercially pure)
- Silicon + Iron: 0.95% max combined
- Copper: 0.05–0.20%
- Manganese: 0.05% max
- Zinc: 0.10% max
- Others each: 0.05% max; others total 0.15% max
- Typical Tensile Strength (as-welded): ~13,000 psi (90 MPa)
- Typical Yield Strength (0.2% offset): ~5,000 psi (34 MPa)
- Elongation: ~25%
- Melting Range: 1190–1215 °F (643–657 °C)
- Available Diameters: 1/16 in, 3/32 in, 1/8 in, 5/32 in
- Package Size: 10 lb box of 36 in cut lengths
Because ER1100 is a low-strength, single-phase filler metal, it should not be used to join high-strength 5xxx or 6xxx series aluminum alloys where yield strength of the joint is critical. Consult the Harris filler metal selection guide or the Lincoln Electric Welding Reference Booklet for cross-alloy compatibility charts.
Harris 1100 aluminum TIG rod is the right choice when joint ductility, corrosion resistance, and aesthetic finish rank above tensile strength. Key industries and use cases include:
- Food and Beverage Equipment: FDA-compliant tanks, hoppers, conveyors, and mixing vessels made from 1100 or 3003 sheet. ER1100 deposits weld metal with virtually no flux residue (TIG process), satisfying sanitary-weld requirements.
- Chemical Tanks and Heat Exchangers: 1100 aluminum resists most organic acids and saltwater environments. Welding 1100 plate with ER1100 rod maintains the parent metal's corrosion resistance in the heat-affected zone.
- Architectural Aluminum: Fascia, trim, gutters, and decorative panels benefit from the bright, smooth bead surface that ER1100 produces when TIG welded with AC current, making post-weld brushing and anodizing easier.
- Electrical Conductors and Bus Bars: High purity means high electrical conductivity. Splicing aluminum bus bars or conductor bars with ER1100 preserves the cross-sectional conductance of the circuit.
- Spin-Formed and Drawn Aluminum: Pressure vessels and spun housings in 1100-H14 or H18 temper are routinely welded with ER1100 because the soft, ductile deposit stretches rather than cracking when the vessel expands and contracts in service.
- Cryogenic Applications: Aluminum does not undergo a ductile-to-brittle transition at very low temperatures. ER1100 weld metal retains ductility at liquid-nitrogen temperatures, making it suitable for LN₂ piping and storage systems.
Successfully TIG welding 1100 aluminum requires attention to pre-weld preparation, machine setup, and arc technique. Follow these guidelines:
Aluminum forms a tenacious oxide layer (Al₂O₃) with a melting point of ~3,700 °F — far above the 1,215 °F melting point of the base metal. Remove the oxide mechanically within 1 hour of welding using a dedicated stainless steel wire brush (never used on steel) or solvent-wipe with acetone. Incomplete oxide removal causes porosity, inclusions, and poor fusion at the toe of the weld.
- Process: GTAW (TIG) with AC current — the electrode-positive half cycle cleans the oxide layer while the electrode-negative half melts the base metal.
- AC Balance: Start at 65–70% electrode-negative (EN) for most 1100 alloy work. Increase EN toward 75% on thicker material to deepen penetration.
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Amperage (approximate, flat position):
- 1/16 in rod on 1/8 in plate: 60–100 A
- 3/32 in rod on 3/16 in plate: 100–160 A
- 1/8 in rod on 1/4 in plate: 150–220 A
- Tungsten: Pure tungsten (green band) or zirconiated tungsten (white band) for AC welding. Ball the tip by striking an arc on a copper block before welding. Ceriated or lanthanated tungsten can be used on inverter machines with high-frequency AC.
- Cup Size: Use a #6–#8 gas lens cup for better shielding gas coverage on flat joints; #10–#12 cup for weld-in-place pipe applications.
- Standard choice: 100% Argon (Ar) at 15–25 CFH. Argon is mandatory on aluminum TIG — helium blends raise arc voltage and heat input, which can cause burn-through on thin material.
- High-speed production: 25–75% He / balance Ar increases travel speed on thicker material (3/8 in and above) by raising heat input without increasing current.
- Pre-flow 0.5–1 second before striking the arc; post-flow 5–8 seconds to protect the cooling puddle and tungsten from oxidation.
Hold the torch at 70–80° work angle, perpendicular to the direction of travel. Feed the ER1100 rod at a shallow 15–20° angle into the leading edge of the puddle — never dip the rod into the arc cone or you will contaminate the tungsten. Use a "walk-the-cup" technique on pipe or freehand on flat plate with a slight oscillation to tie in both toes. Travel speed should be fast enough to keep the puddle from sagging; aluminum loses viscosity quickly as it approaches the liquidus. Pre-heat 1/4 in and thicker material to 200–250 °F to reduce heat sink and minimize cracking risk in the 3xxx series alloys that may be joined with ER1100.
Aluminum filler metal is susceptible to hydration and contamination that directly causes porosity in the finished weld. Follow these handling practices:
- Store in original packaging at 60–80 °F (16–27 °C) and below 50% relative humidity. High humidity causes the aluminum oxide layer to absorb water, which drives hydrogen into the molten puddle and creates sub-surface porosity.
- Avoid temperature cycling (warehouse to cold truck and back). Condensation forms on cold rods when they are brought into a warm shop — allow rods to reach room temperature (30–60 minutes) before opening the box.
- Never reuse rod segments that have been touched bare-handed. Skin oils transfer hydrocarbons onto the filler surface, which crack down to hydrogen at arc temperature. Use clean gloves or a dry cloth when handling cut lengths.
- Use opened boxes within 30 days and keep them closed with the original foil bag resealed or in a sealed plastic container with desiccant packs.
- Discard discolored or pitted rod. A matte grey or frosted surface on a rod that was formerly bright silver indicates advanced oxidation — the rod should not be used for structural welds.
Harris ER1100 aluminum TIG rod is compatible with any AC/DC TIG welder that can deliver stable high-frequency AC current. Recommended platforms include:
- Lincoln Electric Precision TIG 225 and 275 (K2533-1, K2533-2)
- Lincoln Electric Square Wave TIG 200 (K5126-1)
- Lincoln Electric Dynasty series (any AC-capable model)
- Lincoln Electric PTA-17 and PTA-26 TIG torch assemblies
Compatible base metals (primary):
- 1100 aluminum (all tempers: O, H12, H14, H16, H18)
- 3003 and 3004 aluminum (most common with 1100 filler)
- 1050, 1060, 1070 commercially pure aluminum grades
Compatible base metals (secondary / overlay):
- Welding 1xxx to 3xxx series in dissimilar joint applications
- Repair of cast 100.1 and 150.1 aluminum alloys with adequate pre-heat
Do not use ER1100 on 5xxx (magnesium-alloyed), 6xxx (magnesium-silicon), or 7xxx (zinc-alloyed) base metals. The joint will have insufficient strength and may be susceptible to hot cracking in the weld metal.
Q1: What is the difference between ER1100 and ER4043 aluminum TIG rod?
A: ER1100 is commercially pure aluminum (99.0%+ Al) and produces a brighter, more ductile weld with excellent corrosion resistance, but low strength (~13,000 psi tensile). ER4043 contains ~5% silicon, which lowers the melting point, reduces hot-cracking tendency, and improves fluidity — making it the choice for 6061 and 6063 structural alloys. Use ER1100 when welding 1xxx or 3xxx base metals; use ER4043 for 6xxx series structural parts.
Q2: Can I use ER1100 rod on 6061 aluminum?
A: Not recommended. The combination of ER1100's composition and 6061's magnesium-silicon content significantly increases hot-cracking susceptibility in the weld. The resulting joint will also have much lower strength than the base metal. Use ER4043 or ER5356 for 6061 per AWS D1.2 filler metal table.
Q3: Why is my weld puddle pulling away from the edges on 1100 aluminum?
A: This "beading up" behavior usually indicates insufficient oxide removal or poor shielding gas coverage. Clean the joint with dedicated stainless steel brush immediately before welding, verify shielding gas flow is 15–20 CFH, check for leaks in the gas hose and torch body, and increase your arc balance toward more electrode-positive (EP) to maximize oxide cleaning action.
Q4: What tungsten do I use for AC TIG welding ER1100?
A: Pure tungsten (green band) has historically been the standard for AC aluminum TIG and forms a stable hemispherical ball. Zirconiated (white band) holds a ball shape longer, tolerates higher current, and produces less tungsten contamination of the weld. On modern inverter-based TIG machines with square-wave AC, ceriated (grey band) or lanthanated (gold/black band) tungsten also performs well and can handle DC-negative TIG work on the same electrode if you switch processes.
Q5: How do I prevent porosity in my 1100 aluminum TIG welds?
A: The five primary causes of porosity in aluminum TIG are: (1) moisture on the base metal or filler — clean with acetone and allow material to reach room temperature; (2) oxide layer not removed — wire-brush within 1 hour of welding; (3) contaminated shielding gas — use welding-grade argon and check purity (99.999%); (4) air drafts disrupting the gas shield — use a windscreen or increase gas flow to 20–25 CFH in drafty environments; (5) tungsten contamination — inspect and re-ball the tungsten if it develops a pointed or irregular tip after an arc strike.
Q6: What travel speed should I use for TIG welding 1100 aluminum?
A: Travel speed depends on material thickness. For 1/8 in material at 100 A, aim for 8–12 inches per minute. For 3/16 in material at 150 A, 6–10 ipm. For 1/4 in material at 200 A, 5–8 ipm. If the puddle sags or drops through, increase travel speed or reduce amperage. If the bead is narrow and convex with poor fusion, slow down or increase amperage.
Q7: Does Harris ER1100 rod meet AWS certification requirements?
A: Yes. Harris 1100 aluminum TIG rod is manufactured to AWS A5.10/A5.10M classification ER1100. Harris Products Group maintains ISO 9001-certified manufacturing facilities. The product ships with a Certificate of Conformance available on request, and full chemical analysis data is published in the Harris Welding Products catalog. Lot traceability is maintained for quality-critical applications.