Help! My nice one year old Sun-Dura boat cover is black from oak tree sap.

TinBoats.net

Help Support TinBoats.net:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
A few years ago I had the bright idea of trying to wash a tent in a big front load washing machine. I really miss that tent.
Must have been something wrong with your tent then. Old and dry rot probably. If it disintegrates in the washer (front loader) it more than likely needed replacing anyway. A front loader doesn't put much stress on the things inside. All it does is roll them around through some water. I have washed my car covers before with no issue until they start getting sun rot. Then they go to pieces.
 
Instructions for cleaning a boat cover that is saturated with tree sap:

1. Place cover on the ground in an open area away from combustionable materials
2. Generously drench the cover with alcohol
3. Step back several feet
4. Strike a match and toss it on the cover
5. Run!

Obviously just kidding but, any time that you are cleaning a large area with flammables there is a risk that things could go wrong.
I have some old 2cycle mix that should do the job.
You left out step 6. Grab chainsaw and cut tree to the ground.
 
Amazon just had the tarp I was watching reduced to $36. Bought it. Probably spend more on cleaning stuff than the cover costs to replace.

Patiobay Heavy Duty Tarp 10x20FT, 16 Mil Sliver Thick Waterproof Poly Tarp for Outdoor Camping Pool Car Tent, UV Resistant, Rip and Tear Proof Tarpaulin with Grommets and Reinforced Edges

https://www.amazon.com/gp/product/B0C2ZCXXTL/ref=ppx_yo_dt_b_asin_title_o00_s01?ie=UTF8&th=1
Will use it over the boat cover I also bought for about the same price.
The company I bought it from and a lot of others are pretty clear. Do not put in washing machine.
Besides I don think it’ll get it cleaned. If anything it could set the sap in even more. My elbow grease will be more effective.
41E78A20-9D95-4DB3-96E7-9A39229B9B22.jpeg2AC314D7-285F-47AD-9463-9D64553E7B6B.jpeg The way it ran off tells me the fabric guard was working. I’m hoping it’ll help with the removal. If I ever get to it. Still hanging lights and raining today.
And my priorities get in the way. Sap or no sap I’m going fishing next week.
 
The company I bought it from and a lot of others are pretty clear. Do not put in washing machine.
Besides I don think it’ll get it cleaned. If anything it could set the sap in even more. My elbow grease will be more effective.
View attachment 118084View attachment 118085 The way it ran off tells me the fabric guard was working. I’m hoping it’ll help with the removal. If I ever get to it. Still hanging lights and raining today.
And my priorities get in the way. Sap or no sap I’m going fishing next week.
Not going in the washer is generally because it removes the protectant from the fabric, which can be reapplied after drying. A front loading washer is also needed, the bigger the better, hence the commercial use of a laundry. I will just keep the tarp over the actual cover to preserve it. Looking at making a pvc cover support for my boat as well.
 
The company I bought it from and a lot of others are pretty clear. Do not put in washing machine.
Besides I don think it’ll get it cleaned. If anything it could set the sap in even more. My elbow grease will be more effective.
View attachment 118084View attachment 118085 The way it ran off tells me the fabric guard was working. I’m hoping it’ll help with the removal. If I ever get to it. Still hanging lights and raining today.
And my priorities get in the way. Sap or no sap I’m going fishing next week.

Those pic's look about the same as mine. I've used the soapy water and scrub brush while stretched on the boat. It removed some of the gunk, but the cover is still stained.
 
Years ago I used to do the expensive boat cover thing every few years. They all either got ruined by wind, tree dirt, or mildew. They'd be okay for the first summer then get damaged in someway over the winter, and I'd spend the next season trying to get a few more months out of the old cover. I finally gave up and started using recycled bill board tarps. I built a simple to put up wood and PVC support, and I hung a pulley and rope in the tree above the boat.

I ran a loop of rope through the top support pipe and put a series of weighted jugs around the perimeter.
To remove it, I just pulled the rope and lifted the tarp. It was heavy but not too heavy to lift.
The tarp, and the PVC support came off together. When I was done with the boat for the day, I'd simply park it under the
cover, and lower it back onto that boat. I had three pieces of wood cut to fit the top edge of the hull that the PVC frame sat on.
It took only a few minutes to recover the boat.
It all lasted for nearly 20 years, same tarp, same rope, etc. When I moved, the new house didn't haven any big trees so the tarp became more permanent, but I also don't take the boat out as often here since the water is a longer drive away.
The tarp was black on the back side, and even after 20 years the tarp is still 95% water proof. The PVC pipes gave out and got brittle about four years ago and the new support is a bit lower than before so I can slide it on and off myself.

I had mostly oak and willow trees at my old house, they made a lot of dirt but I don't remember ever having any serious issues with sap.
Here, I've got Maple, Cedar, and Pine trees. The pine sap is the worst, but pine trees also aren't the kind of tree you park under. The biggest issue is the seeds and leaves from the maple trees and pollen from the Cedar trees in the spring.

I haven't bought a tarp now in over 20 years, the billboard tarp I bought then was enough to make myself at least four boat covers and I'm still on the first one after over 20 years. The one I found was 20x60 foot and super heavy, it took a front end loader to get it into the back of my truck. It was up for a few months on a local bridge then taken down. Its super heavy duty, they're meant to withstand the worst weather and severe wind. Two entire tarps, all rolled up just about filled the bed of my truck. Cut down to boat cover size they're more manageable though. For a 16ft boat, I cut mine to 20x15ft. I leave the ends a bit less sealed tight so air can get under the tarp. A neighbor used a piece of one tarp to make a homemade shed. Its been there for 10 years now with no leaks.
 
Those pic's look about the same as mine. I've used the soapy water and scrub brush while stretched on the boat. It removed some of the gunk, but the cover is still stained.
Carver also recommends 303 multi surface cleaner and 303 fabric guard.
 
I think we have a winner!
It’s the last thing I thought would work. Even what Carver covers recommended. It’s the only option they give you besides mixing up home remedy they recommend.

It’s 303 Multi Surface Cleaner. It’s safe on all fabric and you can let it sit awhile if needed. They also push retreating with 303 Fabric guard.

I snuck away from what I was supposed to be doing today to try different things so I’d have my game plan together for when I get to actually clean and retreat it.

I tried Seafoam Bugs BGone which worked on the vehicles. After I contacted Seafoam and they said it was safe on the fabric. It didn’t work. I could have let it sit longer but I still don’t trust it on the polyester it’s got some rough stuff in it.

Then I tried Chemical Guys Nonsense . I’ve cleaned some carpet and upholstery with it that was in bad shape. It faded the sap a little but not enough.

Next was Simple Green Pro HD the purple stuff. I might end up putting a patch on that spot.

I said what the heck I’ll try what I clean it with normally. The 303 Multi surface cleaner. I knew it was safe to use. I sprayed a spot and waited a minute then I used a 1” round horse hair brush I use detailing my truck.
I put a little cleaner on it and started in a circular motion and it was working immediately and it was soapy enough I kept scrubbing with the soft horse hair and made the spot bigger. I rinsed it off and it left some sap but it was faded big time and I could see clean khaki. I’m going to get more 303 and use it with my machine. Oh I also tried hot tap water with the brush and it worked even better. So my machine idea should work.
I just have to first acquire more 303 cleaner and 303 fabric protectant (The Admiral is not going to like that $50 spent) so I can treat it as soon as it dries and the weather will have to be dry 24hours.
Here’s a picture or two you can see the clean spot in the cover.
For the bigger area I used that little brush in a hex pattern. Side to side then up and down then circles like I was applying wax. I’ll be using a better brush and may have to do some of it twice but that’s ok. There’s some really dark spots that are being stubborn but I’ll figure them out.
27CC82B0-044B-40D5-BDA8-2BCEA2BCC2EF.jpeg See the clean stripe?
9BA8E538-C36B-4AA4-B019-006DF0A54D3E.jpegThis picture you can see it about half way. It wasn’t completely dry yet but it really showed when it did dry. I was out there in the dark looking at it and smiling.
 
Curious about the black sap. I live in a hardwood forest with lots of oaks. The sap comes down like rain in the spring, but it's kinda yellowish. Sticky as all get out and pretty much resists all soaps. Takes a pretty good scrubbing to get it off of the cars. I don't see it ever coming off of a cloth item.

What I'm wondering is if you aren't seeing road dust or soot settling on the sticky surface? Heck even a smoky fire might deposit black stuff on the cover. If you want my advice, don't worry about it! The cover is a disposable item like a garbage bag. It's meant to get nasty. If it's gross thank your maker that this gunk didn't end up on your boat! Instead of wasting money on cleaning products, save up for a new cover.
 
Curious about the black sap. I live in a hardwood forest with lots of oaks. The sap comes down like rain in the spring, but it's kinda yellowish. Sticky as all get out and pretty much resists all soaps. Takes a pretty good scrubbing to get it off of the cars. I don't see it ever coming off of a cloth item.

What I'm wondering is if you aren't seeing road dust or soot settling on the sticky surface? Heck even a smoky fire might deposit black stuff on the cover. If you want my advice, don't worry about it! The cover is a disposable item like a garbage bag. It's meant to get nasty. If it's gross thank your maker that this gunk didn't end up on your boat! Instead of wasting money on cleaning products, save up for a new cover.
This cover just turned one year old and I bought a good one this go around. I have to contend with the wife (AKA the Admiral). This is after she figured out how much I was spending on the rebuild. All Ancor Marine tinned copper wiring and Ancor marine heat shrink connectors along with the add ons that happened during the process.
I have to get this cover cleaned.

We deal with the yellow stuff in the spring that comes down with the pollen. I’ve always been able to stay on top of it by cleaning it off right away.
I watched this sap as thick as snow for three days come down. Then it just stopped. It was so thick my truck looked like it had spray in bed liner on it.
I’ve lived in Texas my whole life and here for 10 years and never seen anything like it. Some people around here are saying it had something to do with the hard summer we went through with no rain and triple digit temperature for months. Then fall hits and we get cooler all of a sudden along with rain.
Something I always pay attention to is the acorn crop every year because I used to deer hunt every year. And it makes no sense. After that bad of a drought there are acorns everywhere that were falling same time as the sap.
This all happened while I was up grading the brakes on my truck so I was out there in it. Then it took me a week to get around to removing it. the central air in our house went out so I had to fix it first then some family events.
So the sap on the boat cover had time to catch plenty of dirt and other contaminants. That’s why it’s so dark colored. But this still wasn’t the same looking sap we see in spring. It started out dark.
It’s going to cost me more time than anything. I mixed up some Borax , white vinegar and water today and I didn’t mix it enough to dissolve all the Borax powder and I got it on the cover. Everywhere there was a speck of powder on the cover was a clean spot forming around it. After letting the mixture sit a long time I washed it off with a hose and I watched black water run off.
Much more economical and with the cleaning equipment I have I’m not going to wear my arms out scrubbing. Hopefully all I’ll have as far a real expense is a bottle of fabric guard that if done right will last about a year.
That comes out cheaper than an Academy cover which is what I stepped up from.
 
Ok I have a system that I’m confident will get most if not all the sap out of the fibers. It’s going to remove any protection it has. I need to be able to apply something asap. I have no rain here for about 4 days. Problem is I don’t have any 303 marine fabric guard and there is none to be had local. I can order it but I looked everywhere and it wouldn’t be here in time.
I really need to clean it asap. Everyday gives it more holding power.
And I don’t want to clean it and not treat it right away.
I have a full bottle of Star Brite waterproofing spray. This is a Sun-Dura fabric which is polyester but Star Brite says it’s solvent based and will harm cheaper polyester covers and to use their water based.
This wasn’t cheap.
Does anyone know is I’m safe using the Star Brite I have?
Has anyone ever used it on say an economy cover like I had from Academy before I spent the extra and invested in a better cover that’s supposed to last me for years not one year.
If you’ve had experience with Star Brite waterproofing please sha Your knowledge.
 
Yep, it‘s all those new coal electricity generation plants they are building to feed the EVs. Next thing you know they will outlaw boats to bring us closer to carbon neutral.
They’ve already screwed up our portable fuel tanks. It’s all 4 stroke heavy outboards now.
I’m going to run my 1992 40hp Yamaha until it explodes. I’m very adamant about checking everything on the outboard all the time.
I’m going to make it last as long as possibly. When I first got it I had heck finding what I needed to completely rebuild all the carburetors. I have a larger jet in the middle carburetor than what I took out. But when I did the link and sync it adjusted and runs great.
I love unloading it in the morning and letting it idle while I park. I love the smell of two stroke while I’m walking down to the dock.
Sure they’re times I wish it ran like a four like for trolling you can’t even hear a four stroke. Mine doesn’t like to idle very much it builds up and starts smoking normally it only smokes at start up then it runs clean on the Lucas semi synthetic Ashley’s oil.
I took it night fishing on a lake I didn’t know very well and idled everywhere I went. When I started it to head in it smoked like a train. The next morning I put it on muffs but I can’t raise the rpms like I need to so it can clear it’s throat. I had a lot of nasty sludge behind the prop that came out the exhaust. I still haven’t taken it out again but I’m going to in a couple of days and I’ll run it like I stole it. First I’m going to do a decarbonizer here in the driveway and see if any fire trucks show up. 🤣
Then replace the plugs and go straight to the closet lake.
 
Ok I have a system that I’m confident will get most if not all the sap out of the fibers. It’s going to remove any protection it has. I need to be able to apply something asap. I have no rain here for about 4 days. Problem is I don’t have any 303 marine fabric guard and there is none to be had local. I can order it but I looked everywhere and it wouldn’t be here in time.
I really need to clean it asap. Everyday gives it more holding power.
And I don’t want to clean it and not treat it right away.
I have a full bottle of Star Brite waterproofing spray. This is a Sun-Dura fabric which is polyester but Star Brite says it’s solvent based and will harm cheaper polyester covers and to use their water based.
This wasn’t cheap.
Does anyone know is I’m safe using the Star Brite I have?
Has anyone ever used it on say an economy cover like I had from Academy before I spent the extra and invested in a better cover that’s supposed to last me for years not one year.
If you’ve had experience with Star Brite waterproofing please sha Your knowledge.

I haven't used what you are asking about, but if the Star Brite stuff says it doesn't play nice with polyester, then I would be a little leery.

I know you are frustrated over this happening to your newer cover. In truth it is hard to blame the cover for this. No matter how good the cover is, gooey sap falling on it is going to make a mess. I suppose some slick vinyls might be easier to clean. But most breathable fabrics, no matter how good or expensive they are, are likely to have a similar issue. The good news is that goo is on the cover and not on the boat!

The borax, vinegar, & water mix you mentioned in an earlier post seemed to have some good results. Maybe give it a scrub with that home brew. Fingers crossed.
 
Last edited:
Never had one if the newer type sunbrella fabric covers, all my better grade covers including the last one has been made of the vinyl type material, and the last is from semi truck tarp company and all the nasty stuff is easily washed off. They don't come apart from highway use, and never had one crack or split. As far as breathable, mine have small vents sewn into them, never any noticible condensation or mold issues. My last one is over 15 yrs old and still like new but dirty.
 
They’ve already screwed up our portable fuel tanks. It’s all 4 stroke heavy outboards now.
I’m going to run my 1992 40hp Yamaha until it explodes. I’m very adamant about checking everything on the outboard all the time.
I’m going to make it last as long as possibly. When I first got it I had heck finding what I needed to completely rebuild all the carburetors. I have a larger jet in the middle carburetor than what I took out. But when I did the link and sync it adjusted and runs great.
I love unloading it in the morning and letting it idle while I park. I love the smell of two stroke while I’m walking down to the dock.
Sure they’re times I wish it ran like a four like for trolling you can’t even hear a four stroke. Mine doesn’t like to idle very much it builds up and starts smoking normally it only smokes at start up then it runs clean on the Lucas semi synthetic Ashley’s oil.
I took it night fishing on a lake I didn’t know very well and idled everywhere I went. When I started it to head in it smoked like a train. The next morning I put it on muffs but I can’t raise the rpms like I need to so it can clear it’s throat. I had a lot of nasty sludge behind the prop that came out the exhaust. I still haven’t taken it out again but I’m going to in a couple of days and I’ll run it like I stole it. First I’m going to do a decarbonizer here in the driveway and see if any fire trucks show up. 🤣
Then replace the plugs and go straight to the closet lake.
Besides a stabilizer I use Seafoam to keep carbon buildup down and improve the idle on my two stroke outboards. Been using it for years and it makes a big positive difference. My little 1985 Merc 2.2 runs like a top, starts on second pull and all original except plug and impeller.
 
I haven't used what you are asking about, but if the Star Brite stuff says it doesn't play nice with polyester, then I would be a little leery.

I know you are frustrated over this happening to your newer cover. In truth it is hard to blame the cover for this. No matter how good the cover is, gooey sap falling on it is going to make a mess. I suppose some slick vinyls might be easier to clean. But most breathable fabrics, no matter how good or expensive they are, are likely to have a similar issue. The good news is that goo is on the cover and not on the boat!

The borax, vinegar, & water mix you mentioned in an earlier post seemed to have some good results. Maybe give it a scrub with that home brew. Fingers crossed.
I was going to mix some up today but had some Woolite and I tried it with my upholstery brush attached to a drill. Woolite didn’t clean very well and the medium brush I have is to rough. So I just got home from HD with a soft bristle one I needed to add to my cleaning supplies anyway.
I also grabbed a gallon of Totally Awesome. When had a cleaning company on the side in College Station those A&M students would move in and out. I bought this stuff at the dollar store and it cleaned everything.
If the apartment was repainted it removed the over spray.


The Star Brite warning is because it’s solvent base and if there’s an adhesive backing it could mess that up.
The manufacturer recommends 303 Marine fabric guard that they happen to sell. It’s solvent base too.
I also found some water based water and uv protectant in my shop made by Better Boat.
Where I do have success cleaning there’s still sap in some of the little squares that are in the weave. I may have to style and be happy with that which is fine as long as the sap doesn’t cause rotting.
I’ll be mixing up some more Borax solution tomorrow and trying that soft brush on my drill. I think the key is be patient and let stuff work and doing places more than once.

But I’m at the point where tomorrow what I really want to do is take care of a throttle cable issue. Get the portable fuel tank ready so I can switch. Run the motor , run some Mercury power tune through it and smoke up the neighborhood. Put the new plugs in and go to the water and drive it like I stole it. Then catch some bait so Monday or Tuesday I can go to the bigger lake and drift all day dragging bait waiting on those big catfish to give my stuff a good pull.It’s getting to be that time of year and I got a report the big fish are moving out to deep water.

but I’m here scrubbing sap
 

Latest posts

Top