HH-66 Vinyl Cement is designed primarily for flexible PVC vinyl and vinyl-coated materials. It is not a universal plastic glue. Correctly identifying the substrate is the most important step before deciding whether HH-66—also searched as HH66 or HH 66—is appropriate.
Quick answer
Use HH-66 for confirmed compatible PVC vinyl and many PVC-coated or PVC-laminated fabrics. Do not assume it will bond polyethylene, polypropylene, Hypalon/CSM, extremely thin decorative vinyl or an unknown coated fabric. Follow the product maker's approved repair system whenever the item is structural, regulated or safety-critical.
HH-66 material compatibility matrix
| Material | General fit | What to verify |
|---|---|---|
| Flexible PVC vinyl | Primary application | Surface condition, plasticizer level and current RH Adhesives directions. |
| PVC-coated or PVC-laminated fabric | Common application | Confirm the actual coating and use compatible patch material. |
| Vinyl tarps, awnings, tents and covers | Often suitable when PVC | Do not identify by product name or colour alone. |
| PVC inflatables and pool liners | Often suitable | Follow the item's repair manual; special rules apply to structural seams and safety-critical equipment. |
| Polyethylene or polypropylene tarp | Not recommended | Typical woven blue utility tarps are commonly polyolefin, not PVC. |
| Hypalon or CSM boat fabric | Not the default adhesive | Use the fabric manufacturer's approved CSM/Hypalon repair system. |
| EVA traction pad or foam | Not the default adhesive | Use an adhesive approved for the exact foam and backing. |
| Very soft, highly stretchy fabric-backed marine vinyl | Confirm before use | A different flexible upholstery adhesive may be more suitable. |
| Extremely thin sign or wrap vinyl | Not recommended | The solvent system can be unsuitable for thin decorative films. |
| Unknown coated fabric | Do not guess | Obtain the material specification or perform a manufacturer-approved test. |
How to identify the material
- Read the label or manual. Look for PVC, vinyl, polyvinyl chloride, PE, polyethylene, PP, polypropylene, TPU, urethane, CSM or Hypalon.
- Check the original supplier. Product listings, invoices and technical sheets are more reliable than appearance.
- Inspect an unfinished edge. The weave and coating can provide clues, but appearance alone is not conclusive.
- Ask before applying solvent. A small test does not replace material identification when damage would be costly or unsafe.
Application guidance by repair type
Inflatables
HH-66 is commonly used with compatible PVC vinyl patches. Do not use a general online guide to certify commercial amusement equipment, life-saving products, structural seams, valves or heavily loaded attachment points. Read the inflatable-repair guide.
Vinyl tarps and covers
Heavy PVC-coated tarp fabrics are a common use, while lightweight woven blue utility tarps are usually polyethylene. Read the vinyl-tarp repair guide.
Pool liners and flexible PVC membranes
Confirm the liner composition and follow the pool or liner manufacturer's repair limits. Underwater capability does not remove the need for clean surfaces, controlled application and the specified cure.
Awnings and outdoor vinyl
Confirm that the awning is PVC-coated and remove excess adhesive as directed. Exposed excess cement may yellow; do not treat it as a cosmetic seam sealer.
When a compatibility test is appropriate
A controlled test can help when the exact PVC formulation, surface coating or plasticizer level is uncertain but the material has already been positively identified as a candidate substrate. Test on a hidden offcut or noncritical area, follow the current directions and allow the full cure before evaluating adhesion, flexibility, staining and surface damage.
When not to experiment
Do not improvise on life-saving equipment, regulated commercial inflatables, structural seams, load-bearing attachments, chemical-containment systems or another application where bond failure could injure someone or release hazardous material. Use the manufacturer's approved procedure and qualified inspection.
Frequently asked questions
Is HH-66 the same as PVC pipe cement?
No. HH-66 is a flexible vinyl contact adhesive. PVC pipe cements are formulated for rigid piping systems and their specified fittings. Do not substitute one for the other.
Will HH-66 repair a blue tarp?
Usually not. Most lightweight woven blue tarps are polyethylene, which is not the intended substrate. Confirm the material rather than relying on colour alone.
Does “works underwater” mean every repair should be made wet?
No. A clean, dry and well-supported repair is generally easier to prepare, align and roll. Use underwater application only where the current RH Adhesives directions and equipment manufacturer permit it.
How much HH-66 do I need?
RH Adhesives gives a general planning rule of approximately one fluid ounce for one square foot of both bonding surfaces. Actual use varies, so allow for the substrate, application method and waste.
Still unsure what the material is?
Send our technical team the product name, manufacturer, intended service and clear photos before ordering or applying the adhesive.
Shop HH-66Ask our technical teamSources and further reading
- RH Adhesives: HH-66 Vinyl Cement
- RH Adhesives support and compatibility guidance
- HH-66 specification sheet
- HH-66 safety data sheet
This guide provides general educational information. Product formulations and substrate requirements vary. Current manufacturer documents and equipment-maker instructions take precedence.