FAQ
TL;DR: On slit tub rims, you may fit only 3–4 screws, and “the only right thing is to weld plastics.” This FAQ helps DIYers choose a high‑temperature sealing method when rejoining washing‑machine drum casings after bearing replacement. [Elektroda, mrice, post #20437672]
Why it matters: The right joining method prevents leaks, spin‑cycle failures, and repeat tear‑downs after a bearing swap.
Quick Facts
- High‑temp silicone is rated about +265°C; hot cycles around 80°C don’t threaten it per user experience. [Elektroda, leonov, post #17056951]
- Mamut adhesive failed after about 20 washes on a glued drum seam. [Elektroda, gregor7891, post #20436852]
- Plastic welding gives the most durable, flexible joint and is doable at home with heat. [Elektroda, mrice, post #20437672]
- Proven screw method: 3.5×20 mm screws, 2 mm pilot holes, roughly 40 screws used successfully. [Elektroda, Mierzejewski46, post #20437200]
- Sealants reported to work: FixAll (Soudal) or Bostik; Boll car‑window adhesive with activator; Mamut dries too hard. [Elektroda, Mierzejewski46, post #20437018]
What’s the most durable way to reseal a split washing‑machine tub?
Plastic welding is the most reliable method after opening a glued tub. It fuses the plastic so the joint flexes with spin forces. Adhesives or screws alone can let the halves move and eventually seep. As one expert put it, “the only right technique is ‘welding’ of plastic.” Choose welding when you want a long‑term, leak‑free result. [Elektroda, mrice, post #20436936]
Will high‑temperature silicone survive hot wash cycles without hardening or failing?
Yes. Users report high‑temperature silicone rated near +265°C, so normal 60–80°C cycles are far below the limit. As one reply noted, “these 80 will not hurt it.” Use true high‑temp silicone for sealing only, not as the primary structural bond. Confirm cure time before filling the tub with water. [Elektroda, leonov, post #17056951]
Is Mamut adhesive a good choice for drum‑casing seams?
No. A user bonded a cut tub seam with Mamut and the joint failed after roughly 20 washes. That is a clear field failure in hot, wet, vibrating service. Choose alternatives designed for flexibility and constant water exposure, or weld the plastic instead. [Elektroda, gregor7891, post #20436852]
Can a plastics shop weld the tub for me, and is it permanent?
Yes. A local plastics technician can weld the halves, restoring a strong, leak‑resistant joint. One experienced member advised, “He should weld it for you and it will be permanent.” This option suits users without welding tools or practice. Bring a clean, dry tub and discuss compatible filler material. [Elektroda, palmus, post #20436871]
Can I weld the tub at home? How do I do it?
Yes, you can. “If you wish, you can do it at home. Melting the plastic is not that difficult.” Try this:
- Clean, align, and clamp the halves firmly.
- Heat the rim area and base plastic until it softens.
- Fuse a continuous bead around the seam; let it cool without stress.
Use even heat and avoid overheating the plastic. [Elektroda, mrice, post #20437672]
Should I rely on screws or glue to hold the halves together?
Use screws for clamping strength and silicone as a sealant, not as the primary bond. “Silicone serves primarily as a sealant, the screws are responsible for keeping the halves together.” Place screws evenly and avoid over‑torque that can strip plastic. [Elektroda, Mierzejewski46, post #20437171]
What screw size, pilot drill, and screw count have people used successfully?
A documented approach used 3.5×20 mm screws with a 2 mm pilot hole, about 40 screws around the rim. This setup produced two years of leak‑free service on Bosch and Electrolux tubs when paired with proper sealing. Distribute screws evenly to spread loads. [Elektroda, Mierzejewski46, post #20437200]
Why do glued‑and‑screwed seams still leak over time?
Factory bolted tubs use shaped rims and large screws to share loads. After cutting a glued tub, only your small screws carry forces, and drilled holes never fit as well. Without a strong, flexible binder, “we will quickly have a leak at the joint.” Welding avoids this mismatch. [Elektroda, mrice, post #20437672]
What sealants have worked if I don’t weld the tub?
Users report success sealing with FixAll (Soudal) or Bostik, with the halves screwed tightly. A good option is Boll car‑window adhesive with an activator. One caution: “Mammoth, while it is strong, is too hard after drying.” Flexibility matters under spin loads. [Elektroda, Mierzejewski46, post #20437018]
Are two‑component polyurethane adhesives a good option here?
They can suit plastic bonding and remain flexible. One contributor recommended a two‑component polyurethane adhesive and suggested consulting specialists for an exact match to your tank plastic. Retailers like Ataszek can advise on compatible formulations and primers. Follow cure schedules before water testing. [Elektroda, ^ToM^, #20436879]
How can I test whether a glue will adhere to my tank plastic?
Do a simple peel test. Put a drop of your adhesive on the plastic and embed a strip of polyester tape. After curing, peel the tape and check if the adhesive truly bonded or only stuck weakly. Adhesion varies by polymer and copolymer, so test before committing. [Elektroda, Staszek_Staszek, post #20436965]
Can all washer‑tub plastics be welded?
No. Some tank materials or blends resist welding. Inspect the tank for a material symbol, then try a small test weld on a noncritical area. If the bead fuses and holds, proceed; if not, choose a compatible adhesive strategy instead. [Elektroda, Staszek_Staszek, post #20436965]
If I choose bolts, what hole spacing has worked when opening a glued tub?
One documented teardown used holes spaced every 8 cm to split the glued drum cleanly. Even spacing helps maintain alignment for reassembly. Deburr holes and seal screw threads during rejoin to prevent capillary leaks. [Elektroda, Stanislaw elektryk12, #17056793]
Should I reinforce a glued seam with mesh?
Yes, if you must glue, embed a fine polyester mesh into the adhesive layer along the seam. This adds tensile reinforcement “like reinforcement in reinforced concrete.” Keep the mesh fully wetted by the adhesive to avoid voids. [Elektroda, misiek1111, post #20437085]
