Daddles
26th April 2006, 01:16 PM
As therapy from the poxy coating dramas with Redback's sailing bits (see the grrrrrrr thread), I've also been doing the brass rubbing strip along the keel of Sixpence (my Yellowtail - see my avatar).
Whitworths have a 'special' on at the moment, selling 6' lenths of semi round brass strip for under $20 a piece. Perfect length for Sixpence. I bought two and didn't have trim either - one for in front of the centreboard slot right up to the stem and one for behind the centreboard to the end of the skeg. And very nice to work with too - I was surprised at how easy it was to shape the ends and the quality job old fumble fingers here was able to achieve.
I carefully drilled the holes for the screws, countersunk them, then got some fine paper and 'polished' the strips. No, I didn't go for a 'see your face in the thing' polish - hell, these strips will be under the boat and are there to take the bangs and scrapes.
Then to fitting them. I wanted to use brass screws, the old brass on brass rather than stainless on brass business of mixing non alike metals which I don't understand except to know that it's not a good thing (deliberate non-use of grammar to develop that breathless, 'I haven't a clue what I'm doing' feel). Knowing that brass is rather soft, and I'd be screwing into kapur, and that I'd need the screws to pull the brass into place, I predrilled every hole and pulled the strips into place using stainless screws first. Worked perfectly ...
... until I decided it was time to fit the strips properly.
Nice thin line of Sikafex along the bottom of the strip. Dip the screws into poxy to seal the hole in the timber, start screwing. I did the front strip first. Started at the centreboard slot, worked forward, got partway around the curve of the stem ... and twisted the top off a screw :mad:
The dog chose to disappear.
Not sure what to do and knowing I couldn't remove what I'd done without causing dramas, I tried the next screw - this one screwed the head BELOW TIMBER LEVEL :mad:
The dog ordered an aeroplane ticket and passport.
Being an overly confident (translated to mean 'stupid') boat builder, I'd already laid Sikafex along the rear strip so I decided to fit that one while I decided what to do with the front one.
You guessed it, the first screw I tried to put in broke below the surface :mad:
A rescue team of SAS Dogs came to rescue my quivering mutt.
Back to the front strip.
I was able to get a pair of pliers onto one of the broken screws and extract it. For the second, I wound up getting a stainless screw and digging a new hole down the side of the broken screw. I then enlarged the remaining screw holes. As it turned out, I was able to get the front stip on without further dramas and it looks fine - every screw well bedded in poxy, the strip bedded with the Sikafex (yes, I know it'll be hard to get off but don't anticipate removing it very often). The strip doesn't fit as well as it did originally (my messing about put a bend at a screw hole and it doesn't quite sit tight on the timber, but you have to go looking hard to find the gap).
She looks really trick now.
That left the rear strip. First step was to get out the turps and clean up the Sikafex - off the boat where I'd laid the strip and off the strip which still waited to be fitted. Once clean, I dry fitted the strip again with stainless screws, larger than the ones I'd used originally, and had a hell of a time.
This is where a bit of hindsight works well.
You see, I wanted the holes premade so I didn't over stress the brass screws. But because I wanted these screws to hold, I'd used stainless screws a little smaller than the brass ones to follow, thinking the brass would have an easy entry but would still get to cut their own thread in the timber. The timber is a kapur strip glued to the oregon skeg. The stainless screws were a little shorter than the brass. That's right, the stainless screws stopped short of the epoxy layer between the two bits of timber. The brass screws would dig in happily until they hit the poxy layer, then bind up and ping. :mad:
So the holes have been threaded using the right sized stainless screws now and after I've gone to the shops to buy some more brass screws, I'll fit the final strip.
The thing that does annoy me about this is that I'd predrilled all the holes and I'm darned sure I drilled through the poxy layer - the rear strip was the second one I predrilled so I'm guessing I'd learned to judge the depth 'properly' by then, as opposed to having the drill run away and dig too deep like what happened at the front, and didn't actually get through the poxy.
Ah well, another leason learned - two actually, make sure you cut the threads with the right sized screw first off and that brass screws are a looootttttt more fragile than realised.
But Sixpence really does look cute with that white bottom and the brass stip.
Piccies to be posted when I get the second strip on (which won't happen if I stay here on the forum for too long will it :rolleyes: )
Richard
Whitworths have a 'special' on at the moment, selling 6' lenths of semi round brass strip for under $20 a piece. Perfect length for Sixpence. I bought two and didn't have trim either - one for in front of the centreboard slot right up to the stem and one for behind the centreboard to the end of the skeg. And very nice to work with too - I was surprised at how easy it was to shape the ends and the quality job old fumble fingers here was able to achieve.
I carefully drilled the holes for the screws, countersunk them, then got some fine paper and 'polished' the strips. No, I didn't go for a 'see your face in the thing' polish - hell, these strips will be under the boat and are there to take the bangs and scrapes.
Then to fitting them. I wanted to use brass screws, the old brass on brass rather than stainless on brass business of mixing non alike metals which I don't understand except to know that it's not a good thing (deliberate non-use of grammar to develop that breathless, 'I haven't a clue what I'm doing' feel). Knowing that brass is rather soft, and I'd be screwing into kapur, and that I'd need the screws to pull the brass into place, I predrilled every hole and pulled the strips into place using stainless screws first. Worked perfectly ...
... until I decided it was time to fit the strips properly.
Nice thin line of Sikafex along the bottom of the strip. Dip the screws into poxy to seal the hole in the timber, start screwing. I did the front strip first. Started at the centreboard slot, worked forward, got partway around the curve of the stem ... and twisted the top off a screw :mad:
The dog chose to disappear.
Not sure what to do and knowing I couldn't remove what I'd done without causing dramas, I tried the next screw - this one screwed the head BELOW TIMBER LEVEL :mad:
The dog ordered an aeroplane ticket and passport.
Being an overly confident (translated to mean 'stupid') boat builder, I'd already laid Sikafex along the rear strip so I decided to fit that one while I decided what to do with the front one.
You guessed it, the first screw I tried to put in broke below the surface :mad:
A rescue team of SAS Dogs came to rescue my quivering mutt.
Back to the front strip.
I was able to get a pair of pliers onto one of the broken screws and extract it. For the second, I wound up getting a stainless screw and digging a new hole down the side of the broken screw. I then enlarged the remaining screw holes. As it turned out, I was able to get the front stip on without further dramas and it looks fine - every screw well bedded in poxy, the strip bedded with the Sikafex (yes, I know it'll be hard to get off but don't anticipate removing it very often). The strip doesn't fit as well as it did originally (my messing about put a bend at a screw hole and it doesn't quite sit tight on the timber, but you have to go looking hard to find the gap).
She looks really trick now.
That left the rear strip. First step was to get out the turps and clean up the Sikafex - off the boat where I'd laid the strip and off the strip which still waited to be fitted. Once clean, I dry fitted the strip again with stainless screws, larger than the ones I'd used originally, and had a hell of a time.
This is where a bit of hindsight works well.
You see, I wanted the holes premade so I didn't over stress the brass screws. But because I wanted these screws to hold, I'd used stainless screws a little smaller than the brass ones to follow, thinking the brass would have an easy entry but would still get to cut their own thread in the timber. The timber is a kapur strip glued to the oregon skeg. The stainless screws were a little shorter than the brass. That's right, the stainless screws stopped short of the epoxy layer between the two bits of timber. The brass screws would dig in happily until they hit the poxy layer, then bind up and ping. :mad:
So the holes have been threaded using the right sized stainless screws now and after I've gone to the shops to buy some more brass screws, I'll fit the final strip.
The thing that does annoy me about this is that I'd predrilled all the holes and I'm darned sure I drilled through the poxy layer - the rear strip was the second one I predrilled so I'm guessing I'd learned to judge the depth 'properly' by then, as opposed to having the drill run away and dig too deep like what happened at the front, and didn't actually get through the poxy.
Ah well, another leason learned - two actually, make sure you cut the threads with the right sized screw first off and that brass screws are a looootttttt more fragile than realised.
But Sixpence really does look cute with that white bottom and the brass stip.
Piccies to be posted when I get the second strip on (which won't happen if I stay here on the forum for too long will it :rolleyes: )
Richard