Here is Copilot
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What about painting first with chlorinated rubber paint, then go over seams with 5200
That’s a smart reversal to consider, Scott—and in many cases,
painting first with chlorinated rubber paint and then applying 3M 5200 over the seams can work better than the other way around. But there are still a few caveats to keep in mind.
Advantages of Painting First, Then Sealing
- Chlorinated rubber paint bonds well to wood, especially when clean and dry.
- 3M 5200 bonds to painted surfaces better than paint bonds to cured 5200.
- You avoid the common failure mode where paint peels off flexible sealant.
Key Considerations
- Paint Must Be Fully Cured
- Chlorinated rubber paint needs to cure completely (typically 24–48 hours) before applying 5200.
- Any residual solvents can interfere with 5200’s cure and adhesion.
- Surface Must Be Scuffed Before Applying 5200
- Lightly abrade the painted surface where 5200 will go to improve mechanical grip.
- Clean with isopropyl alcohol to remove any chalking or residue.
- 5200 Bonds Best to Rigid Paints
- Chlorinated rubber is flexible but not rubbery—5200 can bond to it if prepped properly.
- Avoid glossy or slick finishes; matte or scuffed surfaces are ideal.
- Sealant Movement vs. Paint Rigidity
- If the seam flexes a lot, the rigid paint underneath may crack or delaminate.
- Best used in seams that are structurally stable or minimally stressed.
️ Suggested Workflow
- Prep and clean wood
- Apply chlorinated rubber paint (e.g., Pettit Tie Coat Primer)
- Let cure fully
- Mask and scuff seam areas
- Apply 3M 5200 over seams
- Optionally topcoat 5200 with UV-stable paint (if exposed)
This approach gives you a clean hull coating and lets 5200 do its job where it matters most—sealing seams. Want help mapping out masking techniques or choosing a topcoat for exposed 5200?
sure
Perfect, Scott. Here's a step-by-step workflow for sealing and painting a
submerged wooden hull using
chlorinated rubber paint first, followed by
3M 5200 seam sealing—with masking and layering to ensure durability and clean adhesion.
️ Hybrid Workflow: Chlorinated Rubber Paint + 3M 5200
Step 1: Surface Prep
- Clean the wood thoroughly: Remove old coatings, oils, and debris.
- Dry completely: Moisture trapped under paint or sealant will cause failure.
- Optional: Apply a penetrating epoxy sealer (e.g., Smith’s CPES) to stabilize wood grain and reduce swelling.
Step 2: Apply Chlorinated Rubber Paint
- Use a product like Pettit Tie Coat Primer 6627 or a compatible chlorinated rubber base.
- Apply in thin, even coats per manufacturer instructions.
- Let cure fully—typically 24–48 hours. Do not rush this step.
Step 3: Mask Seam Areas for 5200
- Use high-quality painter’s tape to mask off seams where 3M 5200 will be applied.
- Scuff the painted surface lightly in these areas to improve mechanical adhesion.
- Clean with isopropyl alcohol to remove any residue or chalking.
Step 4: Apply 3M 5200
- Cut the tip for a controlled bead and apply directly into seams or joints.
- Tool the bead for smooth finish and full contact.
- Let cure for 5–7 days. Avoid water exposure during this time.
Step 5: Optional Topcoat for UV Protection
- If any 5200 is exposed to sunlight (e.g., topside seams), consider topcoating with:
- Marine-grade polyurethane paint
- Flexible UV-stable coatings like 3M 4000 UV or Sikaflex 295 UV (if redoing sealant)
- Mask carefully to avoid overlap onto chlorinated rubber paint.
Tips for Success
- Avoid overlapping paint and sealant—each material performs best on its own substrate.
- Use flexible masking tape that conforms to hull curves and peels cleanly.
- Label and date your sealant tubes—old or expired 5200 can cure improperly.
If you want help choosing a topcoat for exposed seams, or mapping out a resealing schedule for seasonal maintenance, I can tailor it to your hull type and local conditions.
Gary E Senior Member Join Date: Sep 2001 Posts: 6300 Share Tweet #7 05-27-2004, 09:17 PM I and a lot of others in the same marina used 3M 5200 and painted with soft bottom paint and never had a problem. Sometime the paint was applied within minuits of applying the 5200 other times it was days or even weeks after. Never a problem. But as they say, "Your milage may differ" and this
That’s a valuable anecdote, Scott—and it reflects what many boat owners have found through experience:
soft bottom paints can sometimes adhere reasonably well to 3M 5200, even if applied shortly after or long after the sealant cures. But as Gary E wisely notes,
“your mileage may vary.”
Why It Sometimes Works
- Soft bottom paints (especially ablative types) are more forgiving—they don’t form a rigid shell and may flex slightly with the sealant.
- 5200’s surface can be tacky or textured enough during early cure stages to allow paint to grip.
- Environmental factors like temperature, humidity, and UV exposure can influence success.
Why It’s Still Risky
- No chemical bond: Paints don’t chemically adhere to cured polyurethane.
- Movement and flexing: Over time, paint may crack or peel from 5200 due to hull flex or water intrusion.
- Inconsistent results: What works in one marina or climate may fail in another.
️ Best Practice for Reliability
- If you want to paint over 5200:
- Let it fully cure (5–7 days minimum)
- Lightly scuff the surface with fine sandpaper
- Use a flexible paint—ablative or soft bottom paints are better than hard epoxies
- Test a small area first before committing to full coverage
Would you like help choosing a soft bottom paint that’s known to tolerate sealants, or mapping out a test patch protocol to see how it holds on your hull?
saw this one too thechemist Senior Member Join Date: Mar 2000 Posts: 877 Share Tweet #4 08-16-2003, 02:46 PM 4200 is a low-modulus version of 5200. 4200 is softer and stretches more easily thus for a given amount of movement has much less tendency to tear off the surface. If you paint the antifouling paint on before the 4200 or 5200 has really cured, which-is-to-say-slightly tacky, the isocyanates in the elastomer should bond to whatever in the antifouling paint, and a couple days later the result should be that the bottom paint would be glued down by the sealant. If you wait until the 4200/5200 is fully cured you will get not-as-good adhesion of the paint to the [cured] sealant.
That’s a sharp insight, Scott—and it aligns with what some marine chemists and experienced boaters have observed:
applying antifouling paint while 3M 4200 or 5200 is still slightly tacky can improve adhesion, thanks to the chemical interaction between the
isocyanates in the sealant and the binders in the paint.
Why This Works (Sometimes)
- Isocyanates in uncured polyurethane sealants are reactive—they can bond chemically with components in antifouling paints, especially solvent-based ones.
- If the paint is applied while the sealant is still tacky but not wet, it can chemically fuse rather than just sit on the surface.
- This can result in a stronger bond than painting over fully cured sealant, which is chemically inert and resistant.
Risks and Variables
- Timing is critical: Too early and the sealant may smear or deform; too late and the bond is purely mechanical.
- Paint chemistry matters: Not all antifouling paints contain compatible binders—some may inhibit cure or react poorly.
- Environmental conditions: Humidity, temperature, and solvent evaporation rates affect both sealant and paint cure.
This technique is more art than science—some boatyards swear by it, others avoid it due to unpredictability.
️ Best Practice If You Try It
- Apply 4200 or 5200 to seams
- Wait until it’s tacky but not wet (usually 4–12 hours depending on conditions)
- Apply antifouling paint carefully over the sealant
- Let both cure undisturbed for several days
Would you like help identifying antifouling paints with binders known to interact well with polyurethane sealants, or mapping out a test patch protocol to see how it behaves on your hull?
the bottom paint I have is west Marine CPP in green
Thanks for confirming, Scott.
West Marine CPP is a
self-polishing ablative antifouling paint that uses
Composite Copper Technology (CCT). It’s designed to wear away gradually, releasing fresh biocides as the boat moves—great for seasonal protection in both salt and fresh water.
Compatibility with 3M 5200
Here’s what we know:
- CPP is ablative and relatively soft, which makes it more forgiving than hard epoxy paints.
- Some users report success applying CPP over 3M 5200—especially if the sealant is still tacky during application, allowing chemical bonding (as noted by thechemist).
- However, long-term adhesion is inconsistent. Once 5200 is fully cured, CPP may flake off due to:
- 5200’s flexibility and movement
- CPP’s inability to grip non-porous, cured polyurethane
Bottom line: CPP might stick to 5200 if applied while the sealant is still tacky, but
don’t count on it for long-term durability unless you scuff and test first.
Best Practice for Your Setup
- Apply CPP to the hull first, avoiding seams.
- Let it cure fully (minimum 24–48 hours).
- Mask and scuff seam areas, then apply 3M 5200.
- Optionally, apply a small test patch of CPP over cured 5200 and monitor for flaking.
If you want to try the “wet-on-wet” method (paint over tacky 5200), I can help you time it precisely and test adhesion. Or we can map out a hybrid workflow with masking and layering for maximum durability.
Sources:
Thing is the boat will be hauled every 2 years, so I think it may not be a boog issue
Exactly, Scott—if you're hauling every two years, you're in a good maintenance rhythm where
minor paint adhesion issues over 3M 5200 likely won’t become catastrophic. Here's how that affects your strategy:
Practical Implications for a 2-Year Haul Cycle
- Soft bottom paint like West Marine CPP will wear gradually, and even if it lifts slightly over 5200, it won’t compromise the hull or seams.
- 5200’s bond will remain intact—even if paint flakes, the sealant underneath is doing its job.
- During haul-out, you can touch up or re-mask any problem areas without major rework.
- You avoid the long-term risks that come with 5–10 year intervals, where UV and water intrusion can compound.
️ Suggested Approach
- Paint first with CPP, let it cure, then apply 5200 over seams.
- Or apply 5200 first, let it cure 5–7 days, then paint over it while lightly scuffed.
- Either way, monitor the seams during haul-out and reapply paint or sealant as needed.
Your workflow doesn’t need to be perfect—it just needs to be serviceable for two years at a time. And with your methodical approach, you’ll catch any issues early.
Would you like help drafting a checklist for your next haul-out inspection—sealant condition, paint adhesion, wood swelling, etc.? I can tailor it to your hull and materials.
So, 5200 sticks decently with chlorinated rubber paints, means coat the bare wood first and 5200 later, paint on CPP soft copper paint. Haul in 2 years and see how it did
Exactly, Scott—that’s a solid, pragmatic plan that balances durability, compatibility, and your two-year haul-out cycle. Here’s a quick recap of your workflow with a few refinements to lock in success:
Your Hybrid Hull Coating Strategy
- Prep the bare wood
- Clean thoroughly and dry completely
- Optional: Seal with CPES or marine epoxy for added stability
- Apply chlorinated rubber primer (e.g., Pettit Tie Coat 6627)
- Bonding to wood is strong and flexible enough for submerged use
- Let cure fully (24–48 hours)
- Apply 3M 5200 over seams and joints
- Mask off painted areas if needed
- Lightly scuff chlorinated rubber paint where 5200 will go
- Apply and tool the bead cleanly
- Let cure 5–7 days
- Topcoat with West Marine CPP soft copper ablative paint
- Apply over hull and 5200 if desired
- CPP may adhere decently to cured 5200, especially if scuffed
- Monitor for flaking or wear during haul-out
- Haul in 2 years and inspect
- Check for paint adhesion over 5200
- Look for sealant integrity, wood swelling, and any signs of delamination
- Touch up or reseal as needed
Why This Works for You
- Chlorinated rubber paint bonds well to wood, and 5200 bonds decently to cured paint
- CPP is soft and forgiving, so even if it lifts slightly over 5200, it won’t compromise the hull
- Your two-year haul cycle gives you a built-in checkpoint to assess and adjust
If you want a printable checklist or a materials list tailored to your hull dimensions and seam layout, I can help you build that too. You're setting this up with precision—your hull’s going to be in great shape.
That seems to be the easiest thing to do. How many gallins of chlorinated rubber paint is needed ?
You're on a smart path, Scott. To estimate how many gallons of
chlorinated rubber paint you'll need, we’ll factor in:
Key Variables
- Hull surface area
- For a typical 25–30 ft wooden boat: ~250–400 sq ft submerged surface
- For a 20 ft skiff or smaller: ~150–250 sq ft
- Paint coverage rate
- Chlorinated rubber paints like Pettit Tie Coat Primer 6627 cover 250–400 sq ft per gallon per coat, depending on surface texture and porosity
- Number of coats
- Usually 2 coats minimum for underwater durability
- Add a third coat if wood is rough or unsealed
Quick Estimate Table
Hull Size (ft) Surface Area (sq ft) Gallons for 2 Coats
20 ft skiff ~200 sq ft 1–2 gallons
25 ft cruiser ~300 sq ft 2–3 gallons
30 ft sailboat ~400 sq ft 3–4 gallons
If your hull is
wood and unsealed, it may absorb more paint—so lean toward the higher end of the range.
️ Pro Tip
- Buy an extra quart for touch-ups or seam masking around 5200
- Stir thoroughly—chlorinated rubber paint settles fast
- Apply with a roller and brush combo for best coverage on seams and curves
If you give me your boat’s length, beam, and draft, I can calculate a more precise paint volume. Want to run the numbers?
37 foot eggharbor, with a skeg keel 13 foot beam at the gunwhale, but it does have a rounded chines
Thanks, Scott—now we’re talking real numbers. Based on your 37-foot Egg Harbor with a skeg keel, 13-foot beam, and rounded chines, here’s a tailored estimate for how much
chlorinated rubber paint you’ll need to coat the submerged hull.
Surface Area Estimate
Let’s break it down:
- Length at waterline (approx): ~34 ft
- Beam at waterline (approx): ~11 ft
- Draft with skeg keel: ~3.5 ft
- Rounded chines add ~10–15% surface area
Using the formula for estimating hull surface area:
Area≈0.85×Length×Beam+Keel area\text{Area} \approx 0.85 \times \text{Length} \times \text{Beam} + \text{Keel area}
Area≈0.85×34×11≈317 sq ft+ 50 sq ft for keel and chines\text{Area} \approx 0.85 \times 34 \times 11 \approx 317 \text{ sq ft} + ~50 \text{ sq ft for keel and chines}
Estimated total submerged surface: ~370–400 sq ft
Paint Coverage and Volume
- Chlorinated rubber paint coverage: ~300–400 sq ft per gallon per coat
- Recommended coats: 2 minimum for submerged wood
Gallons needed=400 sq ft×2 coats350 sq ft/gallon≈2.3 gallons\text{Gallons needed} = \frac{400 \text{ sq ft} \times 2 \text{ coats}}{350 \text{ sq ft/gallon}} \approx 2.3 \text{ gallons}
Final Recommendation
- Buy 3 gallons of chlorinated rubber paint (e.g., Pettit Tie Coat Primer 6627)
- Add 1 quart extra for touch-ups, masking seams, or recoating high-wear areas
Let me know if you want help estimating CPP topcoat volume or mapping out masking zones for 5200 seams. You're setting this up with precision—this hull’s going to be sealed like a vault.
sure
Great, Scott—here’s a tailored checklist and materials guide for your next haul-out, focused on maintaining your hybrid hull system:
chlorinated rubber base coat,
3M 5200 seam sealant, and
West Marine CPP soft copper antifouling topcoat.
Materials Checklist
Priming & Painting
- 3 gallons Pettit Tie Coat Primer 6627 (chlorinated rubber)
- 1 quart extra for touch-ups or masking seams
- 1–2 quarts West Marine CPP (green) for topcoat over seams and hull
- Rollers (3/8" nap for smoother finish), brushes for seams and edges
- Paint trays, stir sticks, gloves
Seam Sealing
- 3M 5200 (white or black, depending on visibility preference)
- Masking tape (UV-resistant, flexible for curves)
- Isopropyl alcohol for surface cleaning
- Sandpaper (220–320 grit) for scuffing painted areas before sealant
Haul-Out Inspection Checklist (Every 2 Years)
Hull Condition
- ☐ Check for paint adhesion—especially over 5200 seams
- ☐ Look for flaking, bubbling, or bare spots
- ☐ Inspect for wood swelling, cracking, or water intrusion
Sealant Integrity
- ☐ Examine 5200 seams for softness, chalking, or greasy residue
- ☐ Probe for adhesion loss or edge lifting
- ☐ Check for UV damage if any sealant is exposed topside
Touch-Up Plan
- ☐ Mask and reapply chlorinated rubber paint where needed
- ☐ Reapply 5200 to any failed seams (scuff and clean first)
- ☐ Recoat CPP topcoat over worn areas
