Keel Band - #4

[Adam F]

Decided that enough was enough, and after 3 postings on the forum talking about it, I decided to have a go.

 

Looking back to last year Mad Mike (anyone spoke to him?) suggested calling Ferrai's on the Woolsbridge for some Stainless Steel.

 

I called them this morning and they couldnt have been more helpful.

 

I bought 3 lengths of SS to do BW and Splash Out for

[jack]

Adam, If its possable,make sure you countersink screw holes well.If you leave even a little head showing,you will need to drill them out to replace,or renew...Dun it , bin there !..jack

[Seamouse]

make sure you countersink screw holes well.If you leave even a little head showing,you will need to drill them out to replace,or renew

Even a slight protrusion chews the keel rollers to shreds. If there's just a small edge, you can flat them off with an angle grinder. Grinder is also the quickest way to profile the edges of the band.

Have you drilled stainless before?? Keep the drill speed low, use lots of oil and keep the pressure low on the countersink run or it could end up being more hole than countersink. Also control where the swarf goes. Unlike normal steel swarf, it won't rust away. Still razor sharp a year later, not what you want lying around the garage floor.

Steve

[Newboy]

Don't we use oil and water mixed together for cooling and lubricating?!

[Adam F]

I dont know if that was a joke Kam - or serious??....

 

The only way you would get them two to mix is to add an egg to make a mayonaise!!

[Newboy]

It's not a joke, funnily enough I thought the same as you when I first heard it in metalwork back in 3rd year, Mr Stanton smartly pointly out, milk is the mixture of water and fat. It might get seperated if ledt standing but a quick few shake and it's back in mixture form.

 

That's the stuff we use when lathe(?)/turning/milling of metal components. First get a jar, put some water in it, stir it round and round then pour some oil into the swirling water and it will turn milky colour. Squat this liquid onto the drilling space to cool as well as lubricate.

[Maverick Martin]

Newboy its called slurry if I remember correctly from my engineering days

[Brian]

It's not just any oil, it's a soluble oil made especially for the job, when mixed with water it's called "Slurry". You could probably get enough for the job from a local engineering firm. You'll only need about a jam jar full, apply with old brush to keep the drill cool.

[Coddy]

Hi Adam

 

Been thinking about the same for Sammy, will be interested to see how you get on.

 

Are you going the full length and width?

 

Did think about a stainless steel plate that is available shaped for Warrior hulls and other boats for the area near the drain plug which I think is a vunerable area.

 

If you need a hand give me a shout and if I am around I would be happy to help you.

 

Coddy

[Adam F]

Dave,

 

No I didnt think about the keel plate - I have never had a problem here, so I dont think its worth it - the keel band however is invaluable.

 

Ill let you know how I get on. I have a 50mm section at 3000mm long which wil go from the stern to abotu 3/4 the way up, from here it narrows over about 600mm to 20mm width - here I intend to grind the profile.

 

The 20mm section is 1600mm long which takes me up to the winch eye. I may not go this far however, I may stop just where the keel begins to rise.

 

Ill probably do a write up and pictures for the site if I get time.

 

Adam

[Paul D]

Adam,

 

Neo has a keel band if you want to see how that was done.

[shytalk]

adam drilling stainless you needv a slow speed with plenty of pressure use cutting oil such as lubysil slurry only cools lubysil acts as a cutting agent and cools the drill give us a shout if you have any probs

 

the secret one

[Bob F]

My next door neighbour opened up his bosses work shop this afternoon and made short work of drilling and countersunking the SS keel band.

 

Now need to touch up some small areas on the keel before kitting the band.

 

Oh, and I will have to find a tube of "seekaflex" to seal and fix the screws.

 

This is for my Alaska. The keel width is only 12mm wide. A 4 meter length of marine grade SS cost just

[Malroy]

When making your own keelbands, make sure you are using 316 grade stainless.

 

2.5mm to 3.0mm thick is ideal. Bending is achieved fine if you secure at stern first then work your way round the front by bending as you go.

 

On the Warriors, the keelband is tapered from end to end so parallel strips are not suitable. Warrior suggested 3/4" long csk head screws as a max to avoid any going thru', Silkoflex to seal.

 

We have two high powered laser cutting machines at work so I was fortunate in beng able to get mine cut in two lengths (cut from 2500mm long x 1250mm W sheets). This was done measuring the width at 200mm intervals to get the taper right and the holes were also laser cut.

Still had to csk all the holes though, Cobalt cutters and drills help a lot, slow speeds with coarse feed to eliminate the risk of rubbing & burnishing.

[Coddy]

On the Warriors, the keelband is tapered from end to end so parallel strips are not suitable. Warrior suggested 3/4" long csk head screws as a max to avoid any going thru', Silkoflex to seal.

 

Hi Malroy

 

I am not being piccy but surely 3/4" screws are hardly long enough to go through and bite into the wooden keel or are you suggesting that it should not go through the GRP?

 

If that is the case is there enough strength to hold the keel band on?

 

It is just that I am thing of doing this on my Warrior.

 

Coddy

[Adam F]

I have bought 4m of 50mm x 3mm 316 SS to do the larger underwater keel section and 1.6m of 20mm for the bow section.

 

The taper is only over about 300/400mm so I plan to do this manually with a grinder to achive the profile (or leave the taper and just fit the 50mm - havent decided yet)

 

I have bought 10 guage 1 3/4" screws as when you consider the 3mm for the stainless, 3mm for the gel, 4/5mm for the fibreglass plus any voids etc it gives you very little to bite with.

[cullodon]

the very thin cutting discs will cut your profile quickly in a small grinder. could weld the sections together for you if you want

tony

[Malroy]

Hi,

 

Yes it was 3/4" that the guys up at Warrior recommended when I went up there.

 

When you are countersinking the stainless to let the head drop below the surface, you will find that 3/4" still protrudes thru' the strip. When I actually fitted them this worked out fine, going thru' the glass and into the wood.

 

You need a really good and accurate pilot drill. I actually snapped a couple of screws even at 3/4" length but managed to get them out, if you go for more you have a further risk of snapping when biting into the hard wood.

 

On the technical side the actual required amount for a screw to function i.e. to secure, is 1 1/2 times its diameter on positive bite.