Cobra Rods

Cobra Rods (Post Guards)

Internal Boron & Copper Rods for Protecting Wood from Rot and Insect Damage

What Makes Cobra Rods Unique?

Cobra™ Rods are engineered to combat internal decay and insect damage in structural wood components like posts, logs, and timbers.
Their patented formulation of water-diffusible copper and boron migrates through wood via mass flow and diffusion, delivering deep and long-lasting protection.
Unlike surface treatments, Cobra Rods work from the inside out—perfect for high-risk zones like the groundline.

They offer a uniquely high level of solubility (21.3%), allowing active ingredients to reach fungal and insect threats within the wood faster and more effectively than other boron-only rods.
Used by utility companies across North America, Cobra Rods have demonstrated proven protection for over 10 years—even in extreme decay zones like Hilo, Hawaii.

Key Benefits

• Powerful internal protection against fungal decay, termites, carpenter ants, and beetles
• Dual-biocidal system: Copper and boron target both soft-rot and brown/white-rot fungi
• Highly soluble formula for deep migration into the wood
• Safe and environmentally friendly — minimal toxicity, OMRI-listed actives
• Trusted by utility companies and log builders across North America
• 8–10 year treatment cycle means fewer applications needed
• No cleanup or surface staining — completely internal
• Flexible application in decks, fences, log homes, barns, posts, beams, and more

Application Notes

Where to Use:

• Log and timber structures
• Fence and deck posts (especially at groundline)
• Log home sill logs and corners
• Barns, gazebos, and exterior steps
• Any structural wood in high-moisture or ground-contact areas

How to Apply:

1. Drill a hole slightly larger than the Cobra Rod size.
2. Insert the appropriate number of rods per the loading table.
3. Plug hole using Cobra Plug, wooden dowel, caulking, or chinking.
4. Surface may be stained or coated afterward.

Spacing Guidelines:

• Along the grain: max 15″ on center
• Across the grain: max 6″ on center
• Always insert a rod within 3″ of any end joint or high-risk area.

Tools Needed: Drill, hammer, Cobra Rods, sealing plug or putty, safety glasses and gloves.

Coverage Examples (For Recommended Rod Quantities- See full chart below in installation guide)

Wood Size	2″ Rods	3″ Rods	4″ Rods
6″ x 6″ Post (Preventative)	1	1	1
6″ x 6″ Post (With Decay)	5	1	3
10″ Round Log (Preventative)	2	1	1
10″ Round Log (With Decay)	11	2	5
6″ x 8″ Timber	2–3	1	1–2
8″ x 8″ Beam	2–4	1	2
Sill Log	Varies by length – See drill pattern diagrams in install guide

Maintenance Required

Cobra Rods are designed for 8–10 year treatment cycles. After this period, the plug can be removed and rods replaced if needed.
For best results, monitor high-risk zones (groundline, log ends, joints) during regular maintenance and replace rods when depleted.

Frequently Asked Questions

• What are Cobra Rods made of?
  Cobra Rods contain Copper Hydroxide (2.9%), Disodium Octaborate Tetrahydrate (90.6%), and Boric Acid (4.7%)—all recognized as effective, low-toxicity biocides.
• How long do Cobra Rods last?
  Each treatment typically lasts 8–10 years, depending on environmental conditions.
• Do Cobra Rods affect wood stains or coatings?
  No. Cobra Rods are installed internally and do not interfere with surface finishes.
• Can Cobra Rods be used indoors?
  Yes. They are safe and effective for use in interior structural timbers, including log homes.
• Are they safe for pets and children?
  Yes. With oral LD50 values comparable to or better than table salt, Cobra Rods pose minimal health risks when installed correctly.
• Can I use them in conjunction with chinking or caulking?
  Yes. Holes can be sealed using chinking, caulk, or specialized plugs after rod installation.
• Do I need to remove them to reapply?
  No. You simply remove the plug, check condition, and insert new rods as needed.
• Are Cobra Rods approved for organic use?
  Yes. The active ingredients are OMRI-listed for use on organic farms.
• Do they work better than boron-only rods?
  Yes. The copper-boron fusion improves solubility, efficacy, and longevity, especially in wet climates.
• What size rods should I use?
  Rod size depends on the wood dimensions and application type (preventative or remedial). See coverage section or install guide for detailed charts.

Downloads

• Safety Data Sheet (SDS)
• Installation Guide (PDF)