303 on outside & inside?

When applying 303 to latex gaskets, do you apply to both inside and outside surfaces? Any problem with this bothering one’s skin?

not inside
too slippery.


I don’t get it
My latex gaskets are all covered by neoprene over-cuffs. They are not exposed to sunlight and I don’t understand why they need UV protection.

I have not treated the gaskets on my Bomber Gear Drytop and they are 2-1/2 years old and in fine shape.

I treat the gasket
So both inside and outside is my answer. I prefer to just treat the entire gasket which is a defined object.

Should have read your message more carefully. For some reason, I assumed that you meant on the inside of hull of the boat (as in on the inside of a canoe).


There’s no point to 303 on the inside
It’s a UV protectant. How much UV gets to the inside of your seals when you’re wearing your dry suit?

From the Kokatat website.
Latex gaskets need to be treated every 4–6 weeks to prevent drying and cracking. Kokatat recommends 303 Protectant…

303 is not just for UV protection
it is for other things too. One of the guys I paddle with uses it on his wetsuit zippers and the zippers on booties. Also supposed to keep the rubber hatch covers from getting stiff and brittle.

It has a certain degree of lubricity…
…which is why it doesn’t hurt to use it on zippers, but there are better zipper lubes. As for the hatch covers, it’s the UV blocking characteristics that keep them from becoming damaged as you describe. Treating the underside of a hatch cover is unnecessary, unless you leave them off and lying in the sun upside-down. Rubber is not adversely affected by air, although ozone and airborne pollutants can be problematic over time.

OS Systems manufactures seals…

– Last Updated: May-09-06 5:37 AM EST –

...Kokatat doesn't. Here's what OS Systems recommends:


Wash the rubber with a mild soap and water solution to remove all contamination from body oil, pollution, lotions, etc.

Apply silicone to the cleaned rubber. Insure that you are using a food grade silicone grease, oil or spray

NOTE: Applying silicone to a contaminated seal will only trap the contaminants and accelerate the deterioration.


Granted, these instructions are geared toward diving, where UV is not a serious problem. Using a UV protectant on the outside of seals is a good idea for kayaking, due to the UV exposure the seals get when paddling.

If there is a better lubricant
for zippers, please tell me what it is because I was going to put some 303 on mine but I won’t if there is something better I should use. It is almost to the point where I can’t use the booties with zippers because they don’t want to move without tugging really hard and I think I might tear a hole in the neoprene. Thank you.

There are several zipper lubes…

– Last Updated: May-09-06 5:09 PM EST –

...on the market. A quick Google search should turn up a few. Plain ole candle wax or bee's wax does the job just fine. Silicone spray works, too. Probably the most important thing to do to keep a zipper working well is to rinse it thoroughly after using it in salt water.

all added up
really, how much 303 would be “wasted” by doing both sides? I do the inside and outside of my canoe. and that is a whole boat. I also put it on about any surface I can see in the kayak (I don’t have all those fancy hatches…that is why I have a canoe). I just can’t see it being any sort of issue by using too much by coating insides and outsides.


pretty snug fit
I was concerned more with how it might irritate the skin.

I use it on inside and out
and have not had any problems with skin irritation. YMMV.