Shrink Wrap Boat Storage - Huntsville Marine Muskoka

Shrink Wrap Boat Storage….Dangers and Long Term Effects

Shrink Wrap or plastic film boat storage seems like a cheaper alternative to traditional inside boat storage. Signs all over the roads, telephone poles and highways for shrink wrap…$15/ft. $18/ft, $25 or $37.95/foot…but are we sacrificing environmental protection for our boat or even doing harm versus inside storage? You can Google search this for yourself….there are significant risks and problems associated with plastic wrap storage programs the most common of which is black unhealthy mold.

The pitfalls and concerns of Shrink Wrap Boat Storage are significant and can result in increased mechanical maintenance costs due to shortened component lifespans, premature upholstery degradation, corrosion problems, fading issues and one of the big ones…..nasty black mold! Black mold can cause major respiratory problems and is very difficult to completely eradicate from a boat once it gets started. I recently spoke with an owner of a ski boat that utilized shrink wrap and the cleaning costs for mold eradication were $700.00…yikes! Why does Shrink Wrap Storage have these problems and does Inside Storage systems have the same problems?

What are the Problems with Shrink Wrap Storage and Can They be Reduced

  • Plastic Wrap systems maintain a higher constant humidity level in the boat for the entire storage period. Boats tend to be wet by nature and covering them completely with a plastic film makes the problem significantly worse as the moisture cannot adequately escape no matter how much venting is done. Additional venting may in itself add to the problem by allowing snow and rain to enter under the protective wrap. Beads of moisture form on the plastic during temperature swings and fall like rain onto upholstery and carpet surfaces. the process repeats itself over time and temperature swings with the largest moisture loading being the fall and spring months. Excessive moisture levels is what gets the mold started. Marinas or storage facilities can use a number of mold inhibitors inside the boat to reduce the moisture problem as well ensuring that the boat is completely dry before applying the plastic film. Mold prevention is such a large issue in the latest winter storage marina supply booklet there are 41 items to suppress mold and odor problems including sprays, heaters, dehumidifiers, gas producing compounds and desiccants. If you are choosing this method know what you are receiving to reduce your exposure.
  • Temperature loading problems. The plastic wrapped boat is outside in a field and the temperature is at or below 0..what temperature loading problems? There are three basic colors for plastic boat wrap…white, blue and clear. White it is said reduces temperature swings but suffers from snow sticking problems on the outside of the plastic wrap that can result in collapse. Blue has the least amount of snow sticking to it but may have a larger interior temperature swing. Clear well…..every time I see it is looks cloudy due to moisture and snow loading is a problem. The temperature swing inside the boat relative to outside temperature is due to the greenhouse effect of the sun with the plastic cocoon raising the temperature during the day time and then as the sun goes down the internal temperature falling significantly during the evening hours. Measured temperatures inside the plastic cocoon will move above and below the freezing point. Continuous large temperature swings work towards increasing humidity levels in the plastic cocoon. Temperature swing changes cannot be mitigated in shrink wrap systems.
  • High corrosion rates on starters, alternators and metal components. Higher instances of wiring issues, corrosion of wiring connectors and fuse panels. The use of heaters, dehumidifiers and or desiccants can reduce but not eliminate these problems.
  • Chaffing and or marking of the exterior visual gel coat surfaces, windshield frames and wake board towers. Movement of the plastic film almost like continual harmonic vibration due to wind-age is a concern for outer sensitive surfaces. These surface frequently experience marking resulting a flat dull appearance, clear unsightly line blemish’s at or near the tightening hull side rope area which holds the plastic in place against the hull. The use of film under wrap in these areas is required and is not normally part of a quoted shrink wrap price.
  • UV radiation levels on outer and inner surfaces are significantly higher in shrink wrap systems. There is no mitigation for this and clear plastic is not recommended. UV radiation will cause surface fading and damage to all hull, carpet and upolstery surfaces. Does my boat not receive large doses of harmful UV radiation during the boating season…yes. This is why you should be applying sunscreen for your boat surfaces (boat wax) and upholstery surface (303 product or 3M). This is also why boathouses, boat awnings and cockpit and bow cover going over the windshield are recommended in season. UV radiation levels are frequently higher in the winter months.

A key point is to be asking detailed questions on just what is being done during the plastic wrap procedure in addition to how moisture and mold issues are being handled. In the market battle for Shrink Wrap by the foot, less usually means you are receiving less and have a greater exposure to damage during storage periods. Shrink Wrap storage where you have a choice is not your best choice in maintaining the integrity, overall appearance, lifespan and reducing maintenance costs or replacement cycles.

5 thoughts on “Shrink Wrap Boat Storage….Dangers and Long Term Effects

  1. I am new to boating and would like to know if I store a boat inside my garage during the winter months is it better than being outside and does it make a difference which colour shrink wrap is used?

    1. Good day and thank you for question! Inside a normal well kept garage would absolutely be preferable to any for of outside storage in terms of maintaining the interior and exterior boat finish, reducing any mold issues as well as corrosion. When storing a boat in a garage it is advisable to not have any bird seed or any other food source in the garage as frequently mice can be present. Due to mice it is also recommended that all exhaust ports are sealed. It is also recommended that the boat cover not be 100% closed to allow for some air movement. Bounce drier sheets are also helpful in maintaining a critter free storage experience. Always make sure all residual food, candy, gum and such has been removed.
      With respect to shrink wrap colour there are 3….clear, white and blue. White has an inherent problem with snow sticking which if left unattended can lead to failure or collapse of the wrap. We prefer blue due to the snow load in our area and we feel it provides the best UV protection of any of the wraps. We do not recommend clear. Also note there is different thicknesses of plastic which relates to the strength of the wrap and the inherent level of UV protection. The road side shrink warp operations that spring up each fall like weeds normally use the absolute cheapest wrap available and in most cases are not certified in marine engine winterization or maintenance procedures which may result in warranty issues.
      All new boat owners are recommended to carefully follow the detailed winterization instructions in the manual. Premature failure of upholstery due to poor winterization and storage procedure is not a warrantable item. Only a certified Verado technician should be winterizing these high tech outboards.

  2. I live in Canada, which equals snow! My marina forgot to wrap my boat this past season. It sat outside all winter exposed to the elements. They shrink wrapped it in March. Now it’s been opened and my cabin is full of mold, my canvas too doesn’t fit! I’m so upset! The marina is going to professionally clean the mold. But I’m concerned under the carpet lining of my cabin, I’ll still have mold! Help!!!! I think I have an insurance claim on my hands! Any suggestions?

    1. Unfortunately when mold takes hold it will be there essentially forever. The problem is mold spores which can lay dormant for an indefinite period till the right conditions and then they bloom again. Mold guard preventative sprays do help! Water ingression into the affected areas or high moisture levels common in shrink warp systems are not your friend in this situation. Boater’s Chat does not recommend shrink wrap for boats….only in new boat situations where the boat is perfectly dry and properly prepared with inhibitors.

  3. The marina forgot to shrink wrap my boat this past season, until Mar. it sat outside in the snow until then . Snow day on my canvas most the winter! Now it’s been opened up. My cabin is full of mold, and the canvas top leaks and doesn’t fit! The marina is taking responsibility. They are steam cleaning the cabin. I’m nervous the mold will still be behind the carpet lining on the ceiling and walls. Any suggestions?

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