Spearfish 450 floor pressure help!

bomberman · 09 July 2024, 16:17

Hi all,
Does anyone know what the pressure should be for the spearfish 450 airfloor? (It isn't the WB version but if you have that it would be a good starting point!) I think the valve must have been replaced and I can't find what the pressure should be anywhere.
Cheers

Fenlander · 09 July 2024, 16:34

I'd think a call to Nestaway will get you that information. My guess would be 0.8bar.

bomberman · 09 July 2024, 17:02

Thanks Fenlander, have already called them prior to posting but not yet had a response. I have had previous attempts communicating with them in the past that were never responded to, so figured I would edge my bets!

Fenlander · 09 July 2024, 17:14

I mean it's a drop stitch so will need a good high pressure. You could try taking it to say 0.6 bar and see how it felt.

Is this a first inflate of a new to you boat?

bomberman · 09 July 2024, 17:20

Hi Fenlander, Yes thought we would try something a little different this year and it certainly is different. Looking forward to giving it a whirl with my 6hp as the aerotec and 6hp was being overtaken by driftwood!

Fenlander · 09 July 2024, 17:24

It'll be interesting to hear how you get on with the Spearfish... do report back.

bomberman · 09 July 2024, 17:44

Hi Fenlander, Will do, hopefully get at least a few days out on the sea in the next couple of weeks.

chipko · 09 July 2024, 17:45

Hmm. No idea of manufacturers pressure on a spearfish, sorry.

I’d proceed with caution though and start at 0.6 bar as our new moderator suggests, then work up if a tad flexi. If Nestaway not playing ball try a search for an online manual.

We’ve had hp floors vary from 0.6 (Kolibri), 0.7 (Elling) and 0.8 (Aerotec and Honwave) so definitely one pressure doesn’t fit all.

bomberman · 09 July 2024, 17:56

Cheers Chipko, that will have to be plan B if I don't get a definitive beforehand. Hopefully I will get the pressure either on here or from nestaway (I appreciate they are probably quite busy and responding to my query may not be a priority not being the original purchaser of the boat).

bomberman · 12 July 2024, 18:58

Hi all, Just an update, still haven't found out what the floor is supposed to be, took it to 0.6 bar, but there was some flex in it and max speed didn't meet expectations (9.5mph, with 6hp, 2 people on board and a bit of gear). For reference same load and engine on aerotec saw approx 8mph max. If anyone wanted to know the pressure for the tubes and canopy they are all 0.25 bar, 3.6Psi.
First impressions, didn't have to carry too far, maybe 20 to 30m, and I would say it isn't too bad but it is a 2 person job due to the length of it. Good handles one above the bow ring and 2 on the tubes beyond the transom make this task relatively easy. When we came back in, unfortunately the tide was out, slippery rocks etc made it a significantly more challenging task. We had someone help which meant we were able to carry boat and engine attached back up the beach. I know some people use kayak trolleys but on the rocky beach it definitely needs something and with the inflatable floor extending beyond the transom and the flaps of material on the top of the transom, I would imagine only the honwave type wheels would fit but think it would be unstable due to the width.
On the sea, possibly not reporting with the boat at its best as I don't know what the floor pressure should be but, on flat water, it is fine, a bit of chop, it performed pretty well, performance as previously mentioned not as good as was hoping. When the sea state picked up it becomes a little scary in part due to the narrow beam and relatively small diameter tubes. The inflatable bow dodger does a fantastic job keeping of keeping the passenger up front dry.
When operating the outboard I like to sit on the tube and this creates the tube to sit lower in the water especially after I moved the seat forward out of my way. The narrow beam doesn't allow you to stretch your legs out and after a while I found that a little uncomfortable. I dare say if I could use the seat this may mitigate but would need to be double jointed to then operate the outboard. To sum up and ignoring speed/floor flex challenges, it is surprisingly capable and fun. I dare say the boats capabilities way exceed what I would want to be out in, however in the aerotec I would stay out in rougher seas than I would in this, but I am comparing apples and pears there....it is also worth noting this boat has a class d rating, think aerotec and other boats I have owned were all class c but someone can correct me if I have got that wrong!.....to be updated following another outing.

Max... · 12 July 2024, 23:03

I would not be *too* cautious - dropstitch is used by the mile in the SUP industry and for sure quality will vary as does thickness and drop stitch count etc but you can bet just like SIB PVC the vast majority in the world is bought off the shelf from a limited number of Chinese and Korean manufacturers. Even the cr@ppiest supermarket SUP inflates to 12 psi with better established makes performing best at 15 to 20 psi or much higher.

I know you're referencing the Spearfish but IME there is a huge difference with the Bombard floor with the last 1 or 2 psi and I always try and get it to 12 psi on dry land (officially IIRC it's 11.5 or so) - cold water will have an effect of course.

All depends on the structure and how much of a part the floor plays in rigidity...

bomberman · 12 July 2024, 23:39

Thanks Max, certainly worth considering, maybe I will jump to 0.8 bar on the next go.

smallribber · 13 July 2024, 06:06

I am a PSI sort of guy so judging by the Honwave T38 IE2 floor I usually pump that to 10 psi and it is good at that. It does drop a little in the cold water. 10 psi is about 0.7 Bar so in line with what others are saying

bomberman · 13 July 2024, 19:55

Hi Smallribber, thanks, it's a tough one as probably the sensible thing to do would be 0.7 bar as the next step. On the plate the manufacturer is Lodestar and having a look at their marketing materials indicates all their airfloors are 0.8 bar......if I was to make the assumption that the current floors and the floor on the spearfish are made from the same stuff then could make the jump to 0.8 with some confidence......not sure which way I will go, but maybe the cautious approach of 0.7 bar as better a spongy floor than a flat one!!!

smallribber · 13 July 2024, 21:24

Quote:

Originally Posted by bomberman

Hi Smallribber, thanks, it's a tough one as probably the sensible thing to do would be 0.7 bar as the next step. On the plate the manufacturer is Lodestar and having a look at their marketing materials indicates all their airfloors are 0.8 bar......if I was to make the assumption that the current floors and the floor on the spearfish are made from the same stuff then could make the jump to 0.8 with some confidence......not sure which way I will go, but maybe the cautious approach of 0.7 bar as better a spongy floor than a flat one!!!

Yes you can just try it at 0.7 and see how the boat performs. I am sure these pressures have a reasonable factor of safety built in also

bomberman · 14 July 2024, 17:39

Hopefully not boring people, but went to 10.5psi today, didn't have the same chop to clearly compare with the previous pressure but didn't appear to make much difference, 1mph max on top end and still seemed to have flex although as the floor is so long I guess I should expect some flex in the floor.

bomberman · 27 July 2024, 20:27

So to hopefully close the loop, I contacted someone who was selling their Spearfish 450 and it looks like 0.8bar is the appropriate pressure for the floor. This also ties in with the lodestar marketing information for their high pressure floors (manufacturer of the boat) as being 0.8 bar. Hope this helps others.