Spiders under the rub rail

[brackish]

Today was the annual motor out to the shallows (rare on my lake, mostly steep drop offs) in dead calm, anchor, run the spiders out from the rub rail, clean the hull, and gently wash the bottom so as to remove the growth without removing too much ablative paint.  I paint every three years this is the last time I do this before paint this time next year.  Not the most pleasant job, but got it done.

On my 23 there is about a 1/2" gap between the rub rail and the hull on the bottom side.  That is where the spiders live.  I spray them, they come running out about fifty of them around the hull and I evict them.  Then I use a narrow brush to clean that gap and get all the next generation spiders that are bagged up out of there.  Fairly easy to do when standing waist deep and working looking up, very difficult from the deck.

Does anyone else have this problem?  They will be back, just a matter of time, and I'm wondering if there is anything I can put in there that would keep them out.  I'm inclined not to seal the gap off think it might be there for drainage of differential expansion or both, but would really like to keep them out they make such a mess on the boat.

[JTMeissner]

Brackish, I have not tried these, and I'm away from the boat for a while... might come back to find quite the infestation though.

Commercial: http://www.spiderrepel.com

Homemade: https://www.seventhgeneration.com/blog/natural-spider-repellent

-Justin

[bruce]

Just a thought Brackish, if your 1/2" channel is deep enough, would foam backer rod work, without the sealant of course? The open cell type is air permeable, so water would drain, eventually. Might become a mildewy mess. Closed cell might do better. Certainly wouldn't stress the materials, and it wouldn't be super tight seal. Not expensive, if you can find it in shorter lengths. Amazon has some. McMaster Carr has 33 yd. of 5/8" closed cell for $16.38, #77605T442.
https://www.bestmaterials.com/Backer_Rod.aspx#OpenCellSpecs

Might last as long as the paint job.

[brackish]

thanks for the ideas.  Any repellent that requires frequent reapplication is not very practical, both because it is not easy unless I'm standing in the water and there are times I don't get to the boat (45 minutes away) often enough for it to be effective.

The backer rod does have merit.  The key to controlling spiders is to take away their hiding spots.  They build webs close to where they hide but usually at night.  If they have no place to hide in the daytime they might move on.