New to us boat - sweet odor, can't trace it.

[Indysailor]

We just took.posession of a new to us boat. The saloon has a kind of sweet, syrupy odor that we think is probably anti-freeze from winterization. The boat was hauled in late 2025 then sat in a yard until we purchased it.

We have flushed the freshwater tanks a couple times, just using water. We've examined and cleaned every part of the bilge we can reach, verified there is no anti-freeze leaking from the engine, flushed heads and soaked/flushed the shower sumps multiple times, cleaned checked the freezer fridge and we're struggling to locate a source.

When we first got to the boat, there was pink anti-freeze in a few areas of the bilge under the salon and we cleaned those out. I am wondering if this is a residual odor or something else. What suggestions do people have to continue tracking this down?

 

[kappykaplan]

I am wondering if this is a residual odor

This gets my vote.

 

[Davidasailor26]

Beneteaus can hold several gallons in the bilge grid between the pan and the liner. I’d start by pouring your cleansing solution of choice into the bilge area somewhere near the back of the boat, not the main section where the pump is. Let the solution go into the limber holes and dilute or rinse out whatever residue is there. Then go for a vigorous sail and it will all eventually slosh into the bilge pump area.

 

[Indysailor]

Beneteaus can hold several gallons in the bilge grid between the pan and the liner. I’d start by pouring your cleansing solution of choice into the bilge area somewhere near the back of the boat, not the main section where the pump is. Let the solution go into the limber holes and dilute or rinse out whatever residue is there. Then go for a vigorous sail and it will all eventually slosh into the bilge pump area.

Thank you for that reply. We've just been using water, is there a suggestion for a preferred cleaning solution?

 

[Ralph Johnstone]

is there a suggestion for a preferred cleaning solution?

Back in the '70's, industry's answer to any pollution problem was "The solution to pollution is dilution".

That's exactly what you want to do. AF and fresh water are 100% soluble in each other. No detergent required,

 

[Davidasailor26]

If it is antifreeze it should be pretty easily dissolved by water, so it might just be a matter of getting it to the right places.

 

[Stu Jackson]

The cushions may have absorbed some smell. Try this https://en.wikipedia.org/wiki/Febreze

Peggie Hall often highly recommended a cleaning product that one would drop or spray into hard to reach areas. Sorry, but its name escapes me. Perhaps someone else will recall...

EDIT --- I found it: here - Cleaning a stanky bilge?

There is a product that I tripped over at a boat show in Seattle several years ago and brought samples home to test. It's called PureAyre and is available from pet supply stores and Amazon too, as well as directly from the company http://www/pureayre.com and is the only product I've found that will not only eliminate "organic" (sewage, mold etc) odors, but also diesel, oil and even smoke odors. This stuff works! Put a gallon undiluted in a pump garden spray jug (unless you enjoy wearing out your hand on a trigger sprayer) and just lightly "hose down" every surface, nook and cranny in your bilges, inside bait/fish boxes, lockers, and any place else that's smelly--including the inside of your boat shoes!--even the inside of the fridge; it's approved for use around food. It also does a great job on cushions, musty foulies and PFDs. But remember: PureAyre is not a cleaning product! Use it only to remove residual odors after you’ve thoroughly cleaned and removed all the sources of odors.

Do not rinse!!! Just leave lockers—including the fridge or ice box, and all hatches etc open for 24 hours. Run fans if possible, and put soft goods and anything else that isn't bolted down out in the sun all day.

Thank you for that reply. We've just been using water, is there a suggestion for a preferred cleaning solution?

 

[Indysailor]

This is great, thanks everyone! My wife said she didn't notice it as much after going to the grocery and returning, so I'm leaning toward this problem being one of dilution, cleaning, sniffing and repeating until we don't smell it. One nice thing, you really get to know your boat by cleaning every area of it you can touch.

 

[colemj]

First thing is to remove the cushions and mattresses, close the boat up for a bit, then come back and see if it smells differently.

I am very sensitive to the smell of the propylene glycol used in the pink antifreeze, and it smells sickly sweet to me. And I don't have a sensitive nose in general. My wife, who can smell things a year in the future, doesn't smell the antifreeze much at all unless it is shoved under her nose undiluted.

The best way to get rid of smells is chlorine dioxide gas. Set it off, close the boat up tight and get out, and come back 24hrs later to a clean smelling boat with any mold killed, and vermin/insects run out, as a bonus. Amazon.com

Mark

 

[Indysailor]

First thing is to remove the cushions and mattresses, close the boat up for a bit, then come back and see if it smells differently.

I am very sensitive to the smell of the propylene glycol used in the pink antifreeze, and it smells sickly sweet to me. And I don't have a sensitive nose in general. My wife, who can smell things a year in the future, doesn't smell the antifreeze much at all unless it is shoved under her nose undiluted.

The best way to get rid of smells is chlorine dioxide gas. Set it off, close the boat up tight and get out, and come back 24hrs later to a clean smelling boat with any mold killed, and vermin/insects run out, as a bonus. Amazon.com

Mark

We just left one of those in the boat when we left. Glad to here it's worked in your experience.

 

[east coaster]

When we got our 310 it also had a sweet smell that was from the gallons of AF the now previous owner used in many areas of the boat. Washing water and Dawn soap got rid of 95 % of it. The residual odour was removed using pur ayre as Ralph has suggested. It really works and even cleared the air after a misadventure with a diesel fuel hose that chafed its way out of a job. Thanks.