ali hull damage, how much is normal?
Hi guys,
Had a look at an ali boat today it looked like a fairly solidly built boat but the bottom of the hull looked like it had quite a few large dents in it and looked like it was almost wavy? Not sure if this is normal for ali (have only had a glass boat) but I thought it should be fairly straight. The trailer also looked like it wasnt properly setup so all the weight was sitting on the keel, not sure if I should ask the guy if I can have a look under the floor for any broken welds etc or if i should just walk away. I was looking for ali so it could handle a bit of rough handling but is there a point where hull damage will effect performance? The rest of the boat is in fairly good condition for a 10 year old boat and it has what looks like a decent 4 stroke on the back.
meglodon
Posts: 5981
Date Joined: 17/06/10
Walk away
As I understand it the weight distribution should be something like 60% of the boat weight should be on the keel rollers an 40% should be supported by the side rollers/skids.
All those imperfections (dents) under the hull are going to affect how the boat travels and depending on size they could also affect how the transducer of a sounder works.
Swompa
Posts: 3783
Date Joined: 14/10/12
Every deformation =
Every deformation = slower
re the trailer, isn't 99% of the weight meant to be on the keel? Side rollers/slides are for additional support.
Rob H
Posts: 5745
Date Joined: 18/01/12
most yank trailers dont have
most yank trailers dont have any centre rollers, just side bunks.
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Everyone's just winging it.
Peko
Posts: 185
Date Joined: 01/10/14
Wavy Boat
I don't think I would bother to much with the trailer as the boat sounds like its had a pretty hard life. Large dents, almost wavy, no I don't think so. Everything is price dependant of course but in the overall scheme of things I would suggest you keep looking. Just to close out though I have a ali boat and a trailer without rollers. The weight distribution of the boat on the trailer is along the keel with the sides just supported.
Luke
Posts: 167
Date Joined: 02/11/09
Side bunks offer more
Side bunks offer more support then rollers, you'll find almost every yanky trailer has no keel support, they do it for a reason. Can you put some pics up of how bad the hull is? Definatly sounds like its had a hard life!
CCC
Posts: 539
Date Joined: 29/03/10
Yanky trailer are normally
Yanky trailer are normally for Glass boats.
Luke
Posts: 167
Date Joined: 02/11/09
Yep because they need better
Yep because they need better support, rollers can create pressure points and cause some foam filled hulls to delaminate internally. Not saying rollers are a bad thing though, but its definatly worth while setting them up so they all support the hull properly.
Rig
Posts: 2925
Date Joined: 27/12/06
Keel
I don't think it's a good idea to not have keel support on an Ali boat, mine certainly has the majority of its strength in the keel, the bunks are just to keep it steady and if they support to much will end in cracks for sure.
a bit of hull damage is part and parcel of use so I suppose it depends on how much your paying and if the damage has been repaired properly or actually needs repairs, also different if it's plate or pressed
trymyluck
Posts: 908
Date Joined: 06/05/12
walk away mate
walk away mate
Paul_86
Posts: 1449
Date Joined: 27/03/09
I've got an 8 year old ally
I've got an 8 year old ally boat, it's whole life it's been on the same trailer and that trailer is set up for approx 90% + weight sitting on the keel of the boat on the main rollers down the centre of the trailer. The rest of the bits just centre the boat/keep it from rocking around on the trailer.
As for the warped hull tho, I wouldnt touch that with a gomoku fishing rod! That don't sound rite. Any hull will have a little distortion over time but if it seems wavey then that's def a red flag!
randall df223
Posts: 6454
Date Joined: 08/08/11
+1 for that advice. I
+1 for that advice. I reckon a wavy ally hull is a strong indication the boat has been driven too hard thru chop consistently over time and if you could look inside you'lo probably find separation and cracked welds between the frames and hull plate. I'd say buyer beware.
Fish! HARD!
ranmar850
Posts: 2702
Date Joined: 12/08/12
Plate or pressed hull?
Not unusual to see some deformation in a pressed hull, either from hard driving or bouncing off bottom. Mine has some, but there is no cracking. Pressed boats have a built-in amount of flexibility with their construction of frames welded at chine and keel, and rubber between. If the seller and yourself are serious, get him to lift the floor and check-if he won't, walk away.
A plate hull with serious deformation? I'd be very wary of that, usually not so easy to look under the floor.
bergerac
Posts: 66
Date Joined: 25/12/12
Cheers guys, I guess I
Cheers guys, I guess I already knew the answer to that question, thanks for the advice. No 100% sure if it was pressed or plate, looked like a trailcraft clone and the owner was claiming 4mm for the hull which seems kind of heavy for a 15foot boat with a pressed hull. I was custom made in tassy so I cant find any information on the hull, now I know why it looked so cheap. The way it was sitting on the trailer it was barely touching the to side bunks and looked like it would rock side to side when towing, wouldnt want to tie it down with any kind of force either.
The owner wasnt actually there when I looked at it yesterday, I talked to his young son who was quite proud to tell me he gave the boat a hard time when his old man wasnt around.
D_d_001
Posts: 1522
Date Joined: 09/03/13
"The owner wasnt actually
"The owner wasnt actually there when I looked at it yesterday, I talked to his young son who was quite proud to tell me he gave the boat a hard time when his old man wasnt around. "
lol looks like his son would like to keep the boat around for a while longer !
disagree with some of the above but never owned a pressed plate boat so not sure.
my ali (avatar)is plate and hull (12 years old) is absolutely straight as an arrow. I wouldn't touch anything other than straight.
as for the trailer it really does depend on setup but my trailer ...keel rollers only there to guide launch and retrieve. (the keel does not touch when locked on trailer. )
dan1
Posts: 379
Date Joined: 11/07/07
bottom wavey
I Know when i was building my boat the person who was my advice person told me to cut the bottom pannel templates and fold them from the the form the shape as the natural lay of the sheet
this creates tension on the bottom sheets but if fold against the natural lay of the sheet the sheet does not have natural tension and the hull sheets will press up inbetween the ribs and stringers of the boat
possable the cause maybe
bergerac
Posts: 66
Date Joined: 25/12/12
Cheers guys, had a look at
Cheers guys, had a look at another boat today, straight as an arrow and it looked nearly brand new, tempted to grab it even though its got a 2 stroke as it was a decent price and would be worth repowering in a couple years time.
hezzy
Posts: 1519
Date Joined: 27/11/09
the builder of my plate alli
the builder of my plate alli told me years back that all plate alli hulls weight should be mostly keel supported on the trailer, side support should not take much weight, it was for stability mostly
plate hulls should be flat and fairly straight , mine was 5 mm , takes a fair bit to bend it ,
a bad trailer set up or hard driving pounding at high speed could do it
pressed hulls id think would bend easier given the same hard treatment
hezzy
OFW 11
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