Bilge hose material?

[Stuart 28-2]

I have an inboard diesel engine on a 1988 Ericson 28-2.
It seems there are two materials on offer for 1 1/2" bilge hose: Polyethylene and vinyl. Looking online it seems polyethylene has good resistance to diesel and engine oil and a host of other chemicals. However, polyethylene hose I can get my hands on seems cheap and "plasticy" to me.
Makes think I'll be replacing it again in a couple of years and it's a job I'd like to do just once.
Anyone have recommendation or warning on hose material for the manual bilge pump.

 

[Loren Beach]

Our '88 was built out with some reinforced black rubber hose, i.e. the 3/4" version of "exhaust hose" for some runs and a ribbed vinyl white 1.5" hose product that was tough, but also getting brittle by the time I replaced them in '08. I went with vinyl translucent/black product with integral harder plastic spiral reinforcing. Smooth bore for less friction and it clamps firmly. This was from a local industrial hose & fittings shop.
There are good products from chandlers, like Trident 147. And, that's just one good product.
Pix: https://ericsonyachts.org/ie/ubs/new-bilge-hose-april-2016.480/
Some pix of our 1.5" head hoses, after replacement, in this thread --- https://ericsonyachts.org/ie/threads/new-holding-tank-piping-valves.6251/page-2

It's good to use high quality hose, whether for head or bilge, even tho they will cost more per foot. I like to shoot for a 20 year (min) overhaul cycle on this sort of project.

 

[Rufus McCool]

You may've solved your concerns by now, however I recently learned of two difficulties with the bilge hoses. My 1990 28-2 used the same hose Loren described - 3/4" reinforced black rubber and 1.5" vinyl. The black hose is on the two diaphragm pumps - one for bilge, the other for shower sump. The first problem came with the white ribbed 1.5" hose to the manual bilge pump. I accidentally broke that hose while working on the battery switch (in the same congested area). I decided I would replace the hose, because obviously it was brittle. Brittle is not really the best word to describe it. The hose had become as stiff as sch 40 pvc pipe. It had essentially conformed itself to the shape and location where it laid. I had to cut it out in pieces and use a hair dryer to soften it. It took days with serious wrestling to remove it, thus I decided to not remove the entire section running to the transom. So, beware of 30 year old vinyl ribbed hose in these boats. Age apparently petrifies it. I battled removing that hose and nearly lost the battle.

The second problem came when I decided to remove one of the 3/4" rubber hoses from the diaphragm pump. All went well until the section that curls under the back corner of the fuel tank headed to the transom. Apparently Ericson installs these hoses to the underside of the liner prior to placing, and screws zip-ties holding them to the liner. This prevents pulling individual hoses out one at a time. Access is basically non-existent , so cutting the zip-tie required amazing contortions beyond human flexibility.

Both jobs at the onset seemed simple, but resulted in a torturous and painful struggle.

I recommend the exact replacement hose Loren used, and use it on both 3/4" and 1.5" applications. I found it at Defender. I'm hoping the flexibility will last for years to come. Time will tell.

 

[Stuart 28-2]

You may've solved your concerns by now, however I recently learned of two difficulties with the bilge hoses. My 1990 28-2 used the same hose Loren described - 3/4" reinforced black rubber and 1.5" vinyl. The black hose is on the two diaphragm pumps - one for bilge, the other for shower sump. The first problem came with the white ribbed 1.5" hose to the manual bilge pump. I accidentally broke that hose while working on the battery switch (in the same congested area). I decided I would replace the hose, because obviously it was brittle. Brittle is not really the best word to describe it. The hose had become as stiff as sch 40 pvc pipe. It had essentially conformed itself to the shape and location where it laid. I had to cut it out in pieces and use a hair dryer to soften it. It took days with serious wrestling to remove it, thus I decided to not remove the entire section running to the transom. So, beware of 30 year old vinyl ribbed hose in these boats. Age apparently petrifies it. I battled removing that hose and nearly lost the battle.

The second problem came when I decided to remove one of the 3/4" rubber hoses from the diaphragm pump. All went well until the section that curls under the back corner of the fuel tank headed to the transom. Apparently Ericson installs these hoses to the underside of the liner prior to placing, and screws zip-ties holding them to the liner. This prevents pulling individual hoses out one at a time. Access is basically non-existent , so cutting the zip-tie required amazing contortions beyond human flexibility.

Both jobs at the onset seemed simple, but resulted in a torturous and painful struggle.

I recommend the exact replacement hose Loren used, and use it on both 3/4" and 1.5" applications. I found it at Defender. I'm hoping the flexibility will last for years to come. Time will tell.

Thanks. So much of that is so close to my experience it could almost be my own words. I found the heat gun is pretty much essential before touching that 1.5" white ribbed hose. However, for sections not removed I think the heat may make it even more brittle over time.
On my 28 the 3/4" black reinforced rubber hoses lay through two opposing near 90 degree turns adding to the pain.