Caulk: what Claude and GPT would buy
Two AI models chose on their own, with no web access. Nobody tested these products: this is what each one says, and how to check it.
They disagree: Claude chooses OSI and GPT chooses DAP
In Industrial & Scientific, Claude and GPT choose the same brand in 52 of 107 categories.
Claude Opus 5.5 · October 28, 2026
OSI Quad Max (line)
A hybrid polymer sealant that grips most exterior substrates, takes large joint movement, tolerates damp application and can be painted, so one tube covers most general sealing jobs.
Not for: Fire-rated penetrations, stove or engine heat, or anyone who needs a cheap paintable interior trim caulk.
GPT 6.1 Sol · November 10, 2026
DAP DYNAFLEX 230 (line)
A versatile, paintable indoor/outdoor sealant with lasting flexibility and easy water cleanup for common sealing jobs.
Not for: Continuous submersion, structural bonding, or applications requiring pure silicone.
Which one fits you
interior trim and paint prep
DAP Alex Plus (line)
Easy-tooling acrylic latex that cleans up with water and paints quickly.
Not for: Wet areas or exterior joints with real movement.
tubs, sinks and showers
GE Silicone 2 Kitchen & Bath (line)
Waterproof, mildew-resistant 100% silicone for permanently wet joints.
Not for: Anything you plan to paint.
Check before you buy
Where to find OSI Quad Max
- Lowe's
- Builders Warehouse
Shops seen in search results on November 6, 2026. A shop missing here may sell it too. Nothing was checked by a person.
Brands that matter
- OSI: Henkel's professional sealant brand, known for hybrid polymer exterior sealants.
- DAP: Broad consumer range from basic latex to elastomeric and silicone.
- GE: Long-standing silicone sealant line for kitchens, baths, windows and doors.
- Sashco: Specialist in very stretchy elastomeric exterior caulks.
- Red Devil: Budget to mid-range caulks and specialty compounds.
What to avoid
- Using basic acrylic latex on exterior joints that move.
- Caulking over old silicone, which new caulk will not bond to.
- Bridging wide or deep gaps without backer rod.
Questions
Caulk or sealant: is there a difference?
The terms overlap. 'Sealant' usually means a more flexible, higher-movement product (silicone, polyurethane, hybrid), while 'caulk' often means a cheaper latex product for static gaps.