Page 2 of 37 FirstFirst 123456712 ... LastLast
Results 16 to 30 of 551

Thread: Tom Cat

  1. #16
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem Jig

    I finished the Stem Jig yesterday. The major bend area is fabricated from a couple of pieces of chipboard with an inner layer of more chipboard pieces. These pieces are there to not only provide enough vertical width but to also provide strength along the clamping pressure lines. As you can see in the pics I have also made a few blocks for those areas of less stress during the bending process and they will also play a critical role when it comes time to glue up. The second pic shows the Inner Stem template placed on the jig to see how it looks.

    Stem Jig.JPG Jig with Inner Stem Tmplt.JPG

    In addition I have attached further pieces to the bottom of all these to make it easier to screw to the stem lofting and to provide some clearance between the board and the jig itself. The idea is to place some plastic sheet over the stem lofting and screw down the jig pieces over that after using packaging tape to protect them from glue. I’m hoping this will enable the excess glue to ooze out and down under the laminates so as not to create a big mess for the laminates to wallow in and not sit down square. We’ll see.

    But first the bending….I’m hoping to make the process go easier by soaking the planks for 24hrs prior to steaming them so had to build a temporary bath out of some right angle colourbond roof edge flashing I had lying around. SWMBO would not allow the planks in the son’s bath tub! It appears I will have to do the 16 laminates in two separate goes….I don’t want to undo the clamps once they’re in place to put the extra laminates in, just case I lose the bend in the first lot. Also no room to put 16 laminates in my temporary water bath anyway.

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Age
    2010
    Posts
    Many





     
  3. #17
    Join Date
    May 2003
    Location
    South Oz, the big smokey bit in the middle
    Age
    67
    Posts
    4,377

    Default

    Quote Originally Posted by Dry Water View Post
    In addition I have attached further pieces to the bottom of all these to make it easier to screw to the stem lofting and to provide some clearance between the board and the jig itself. The idea is to place some plastic sheet over the stem lofting and screw down the jig pieces over that after using packaging tape to protect them from glue. I’m hoping this will enable the excess glue to ooze out and down under the laminates so as not to create a big mess for the laminates to wallow in and not sit down square. We’ll see.
    No need to worry about that mate. Just put your plastic down, screw the blocks to the board and laminate flat onto the bench. Sure, glue will seep out but youv'e got to dress that face anyway and the excess glue comes off with it.

    Make sure you leave plenty of width in your strips. You won't get them all down flat and so will have to take a fair bit off to get your stem flat on either side.

    Lumps of angle iron work very well - strong, rigid and relatively thin (so they don't take up precious clamping width).

    The plastic packing wrap is very effective, use it everywhere you don't want something to stick.

    You haven't mentioned it but do you know about having a sacrificial strip on the outside? Cover it with packing tape so it doesn't stick and it stops your outer laminate from splintering.

    But first the bending….I’m hoping to make the process go easier by soaking the planks for 24hrs prior to steaming them so had to build a temporary bath out of some right angle colourbond roof edge flashing I had lying around. SWMBO would not allow the planks in the son’s bath tub!
    I've done a number of laminates now, inner and outer stems, knees, frames in both oregon and kapur. You don't need to soak or steam the strips, just make sure they're thin enough (which you do by trial and break ).

    It appears I will have to do the 16 laminates in two separate goes….I don’t want to undo the clamps once they’re in place to put the extra laminates in, just case I lose the bend in the first lot. Also no room to put 16 laminates in my temporary water bath anyway.
    16? Sounds like a hell of a lot. Are you sure you're not supposed to be making an inner stem, building the hull to that, then adding an outer stem after it's been planked?

    Richard
    dredging his memory and hoping he's not digging up sludge

  4. #18
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem Build

    Richard
    Many thanks for the feedback ……..however, as you can appreciate I’m committed to the jig I’ve already made. Your tip on the width has come at a timely moment as I do not have a lot of room to spare width wise. Funny how something as simple as your statement on width makes one ponder that particular comment. In my case I will have to make sure everything is level during bending and gluing process. I’ve only got about 5-6mm to play with. My strips have been put thru a jointer and thicknesser so I’m confident I’m coming off a square base.

    Your tip on the sacrificial strip is a beauty and I will certainly do that. I had thought to knock off the sharp corners but this addition will be great.

    I am making just the Inner Stem. It’s a monster at 100mm at its greatest thickness and my strips are 6-7mm as per the plans. I am thinking I will stagger the strips to reduce the wastage as the maximum laminate width is in the middle of the radius. If I don’t there will be a lot of wastage as the bevels are put in and I can use the offcuts to laminate the Transom/Keelson knee or the Mast Step.

    I think the steaming will provide some good experience and add a skill to my shed so I will continue with that. I’m certainly not confident that the KD T. Oak will bend without this assistance at this thickness and I’m not into the trial and error process at the price the oak is. It’s also bad enough that I’ve got 16 strips without making more! The finished Inner stem thickness comes down to about 75mm after planking is complete and then dressed off for the outer stem. The Outer is about 50mm giving a finished total of approx 125mm. It’s a doozy but then it’s a cat boat with a lot of stress up forward.

    I really appreciate the feedback. It was one of the reasons for starting the thread in the beginning. I had hoped to get some response and it’s all great stuff in helping thru the build.

  5. #19
    Join Date
    May 2003
    Location
    South Oz, the big smokey bit in the middle
    Age
    67
    Posts
    4,377

    Default

    Keep us posted on the steaming, it's something I want to get into at some point.

    Sounds like she's going to be a solid boat. What thickness ice will you be breaking through

    Richard

  6. #20
    Join Date
    Jul 2005
    Location
    'Delaide, Australia
    Age
    65
    Posts
    8,138

    Default

    Howdy,

    Green timber responds very well to steaming - dried timber will still respond but not as well.

    Thinner will help.

    Steaming is quite interesting - it allows the molecular bonds in the timber to become mobile. The heat is the main thing - but you can't use dry heat very successfully as overdrying makes the timber more brittle and likely to break.

    MIK

  7. #21
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem – Steam Bending Complete

    It was all a bit of an anti-climax I’d have to say. I had been concerned on a number of fronts. The first being had I enough steam to do the job with my steam box set up. There was no issues at all there……. one relief. The second was the ability of the KD T. Oak to bend without snapping. I realised too late that the original boards had the grain running in the wrong direction to give me the grain parallel to the bend after re-sawing. The result was the grain at 90 degrees to the bend in my laminates. So…a mild concern….not! The soaking was no longer an idea but now was a must. To assist matters further I knocked of the corners as suggested by Richard previously.

    As mentioned previously the water bath I made was not big enough to do all the laminates at once so I dunked only half of them in thinking that if things go wrong I had only committed half the expense of the wood. I needn’t have worried. The steaming process the next evening went very smoothly and the timber came out of the box after 15-20 mins and wrapped around the jig no problem. This was completed with some help from my son to hold onto the laminates while I worked them around the jig putting clamps on as I went. It was all over in about 10 minutes and had plenty of time thereafter to adjust clamps etc to achieve full contact all around the jig.

    The next step was to do the balance of the required laminates. Here I was concerned that if I let the clamps go to put the new ones on I would lose the existing bend. New idea! Considering the bulk of the timber is only required in half the length of the stem I could cut the remaining laminates down and bend them in place without letting go the end clamps. I should be paid money for this. It worked out just fine with the help of some small jigs to keep the laminates in contact. See pics. To top it all off I didn’t soak the last lot in water and also forgot to knock the edges off but around they went…no problem.

    I had finished them last Sunday and so to the next concern…..when I let the clamps go to glue up will they go back without breaking? I had completed the jig on a separate board away from the lofting and realized that maybe I would need more room when it came time to glue up so I decided to move everything back to the lofting. I did this last night after covering the lofting with a lot more plastic sheet, taped up the jig so the glue wouldn’t stick and let the laminates loose of the clamps and put them back with no worries.

    1 Stem Jig Laminates.jpg 2 Stem Jig Laminates.jpg 3 Stem Jig Laminates.jpg

    So finally I‘m at the end of the steam bending saga with just all the worry about the glue up to come. I’ll leave the wood in the jig for another few days so that it definitely gets the idea that this new shape should be how it will be from now on. One further point….when relocating everything I have allowed for a small amount of spring back. Not much, about 5mm at the top and about 3mm at the bottom. All guess work but I have plenty to work with. We’ll see.

  8. #22
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem Glue up

    Well....it's all gone off according to plan. My anxiety with the release of the steam bent laminates from the jig has been unfounded and the subsequent glue up has proven to be as expected with the one exception that I over estimated the springback. When the springback formula says 1.35mm it doesn't mean allow 4mm! Anyway not to worry I have plenty of wood to work with. I'm still in admiration of the formula though as the springback was just as the result should have been. One wonders why we think the experienced don't know what they're doing!

    My template was a furfee so I eneded up using carbon paper and the original Mylar template to provide the pattern for sawing the stem to proper size. It just goes to show you should check anbd recheck everything you do when you're an amatuer at work. The pics show the glue job, released, finished to size and ready for sawing to size ready for the bevelling. I love my new jointer and thicknesser...they have made this transition a "no problem" affair. If you can afford them, get 'em! It makes the whole process that much more simplified. I somehow cannot imagine how I would achieve the finish and accuarcy with my old hand tools.

    It's now onto the cutting and bevelling before turning my attenetion to the transom. I'm having trouble with the pics so will come back when I've sorted it out.

  9. #23
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem Glue up Pics

    For some unknown reason I always have trouble getting the size of the pics down to an acceptable level!

    DSC01120.JPG DSC01117.JPG DSC01118.JPG DSC01119.JPG

    Hopefully the pics are self explanatory.

    Laurie

  10. #24
    Join Date
    May 2003
    Location
    South Oz, the big smokey bit in the middle
    Age
    67
    Posts
    4,377

    Default

    See. Easy wasn't it. Don't know what you were worrying about.

    **ducks and runs away**

    Well done mate. Great feeling isn't it. I love laminating, the end result is so far away from the individual bits it feels as though you've done something the Vatican wouldn't approve of

    Richard

  11. #25
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Stem Bevelling

    This has been a hard job! …I think a combination of the KD T.Oak with the many epoxied laminations made the task more difficult. I commenced with a draw knife and took it down as far as I dare to get rid of most of the waste leaving about 3 or 4 mm to come off. Then took to it with a jack plane, then block plane, spokeshave and finally chisel and scraper. I think the block plane is the weapon of choice for getting it right down to a chisel and scraper level. I wasn’t game to even contemplate the electric hand plane for the job.

    Speaking of hand tools, I continually have problems with the spokeshave and I think it’s my sharpening angles and technique. Can anyone give me a clue on this? Or a good web site to go to for some free instruction? I don’t appear to have any issues with my other tools just this little sucker.

    Hopefully the lofting has provided what is required but knowing me I will have to attack it again for final adjustment of the mating surfaces for the planking. However, it’s been a good exercise in restraint not to go at it like a bull at a gate. It’s taken approx 4 hours all up to complete the stem bevels. At 1.5 to 2 hours per session that’s about a third of my allotted building time for the week gone. I’d hate to be trying to make a living at this. Being under no time pressure to get a job done makes it what it is….a very pleasurable pastime.

    DSC01129.JPG DSC01138.JPG DSC01140.JPG DSC01139.JPG

    DSC01146.JPG DSC01144.JPG

    The bevel comes to a point for planking and is planed back on completion of that to 38mm to provide a bearing surface for the outer stem. Getting the apex right was the tricky part…. just wanted to leave the thin pencil line down the front centre on completion.

    With the Apron bevel yet to come it appears even more daunting than the Stem. However, there are no laminations to contend with so it may go a little easier.

    It’s now onto the jig for the curved Transom. It’s all so much fun!!

  12. #26
    Join Date
    May 2003
    Location
    South Oz, the big smokey bit in the middle
    Age
    67
    Posts
    4,377

    Default

    I love my block plane, amazing weapon for so many things.

    I too have problems getting an edge on a spokeshave and then using it. Tips would be appreciated.

    Richard

  13. #27
    Join Date
    Jun 2005
    Location
    Sydney
    Posts
    3,096

    Default

    You blokes using a MkII Veritas sharpening jig?

    I could never sharpen freehand too well, and small blades were always easier for me to stuff up.

    See if you can check if the back of the blade meets the face of the spokeshave without gaps and 'high points'.

    Sharpen as per a normal plane blade. Make sure the back of the blade is polished.

    If the blade is a bit too short to fit in the Veritas jig, use a bit of metal to make an extension for the blade, use the height adjuster holes in the blade and small bolts to attach blade to 'extension'.

    I have old Stanley 151's - flat and convex bottoms... sometimes they need a piece of soft copper sheet/shim to fit between blade and body to pack up any high/low points and to close the mouth a bit. I've used the aluminium from a can of Milo as well, its a heavier alfoil than usual.
    Or you can file away if you feelgame.

    Pull the spokeshave in a way that maintains the angle of the blade at the same angle of a plane blade.
    You can 'tilt' the tool and lift up the back of the spokeshave, taking the blade off the wood... so hold it down well.
    Set a fine cut and slowly work the blade out till it cuts as deep as you want to go. test, adjust, test adjust.

    Skew the spokeshave, as you would a plane, if needed in tricky grain.

    If any of this is helpful, great... if not, let me know and I'll have another think about my early efforts and what I was doing wrong.
    Cheers,
    Clinton

    "Use your third eye" - Watson

    http://www.flickr.com/photos/clinton_findlay/

  14. #28
    Join Date
    Jul 2005
    Location
    'Delaide, Australia
    Age
    65
    Posts
    8,138

    Default

    Quote Originally Posted by Dry Water View Post
    For some unknown reason I always have trouble getting the size of the pics down to an acceptable level!

    Laurie
    If you are using windows xp (or maybe vista) you can use this tool from microsoft.

    Go to this page
    http://www.microsoft.com/windowsxp/d...powertoys.mspx

    Download the image resizer listed in the left column.

    Install it.

    Then you can select a picture or a group of pictures - right click them so the menu pops up beside the cursor. Select "resize images" - it will give you some size options - choose "OK" and it will create the resized version in the same directory all relabelled so you can identify them.

    MIK

  15. #29
    Join Date
    Dec 2007
    Location
    Toowoomba
    Age
    72
    Posts
    373

    Default Transom Mould

    This was a simple exercise and I used an old bar top that was lying around to make the two cambered beams. I followed the plans to the letter to get the right shape and also used the same number and thickness of staves.

    DSC01149 (Small).JPG DSC01151 (Small).JPG DSC01148 (Small).JPG

    I have purchased some BS1088 Maple 6mm ply for the two inner laminates and will use 6mm boards resawn from NG Rosewood to make up the last layer.

    Just as an aside I drove to Brisbane to get the ply from Boatcraft as the prices up here in Toowoomba are 25% more expensive. I figured that it was still cheaper in petrol to go down and pick up a couple of sheets. I got a sheet of 12mm for the centre board and rudder while I was there. This will allow me to get the backbone, rudder and centre board completed before building the strongback and pulling up the lofting. Having the lofting available for checking the work is a great bonus.

    If I have sufficient T.Oak left from the my earlier work on the stem I’ll also begin the fabrication of the Mast Step. Just another little opportune project if I have the required stock. I’ll definitely have left over epoxy that I will be able to utilise and not have to throw it out.

    Thanks Mick for the Resizing hint ………..it works great and is easy to use and………thanks to Clinton . It’s early days but when I’m back in the shed I’ll have a go.
    Laurie

  16. #30
    Join Date
    May 2003
    Location
    South Oz, the big smokey bit in the middle
    Age
    67
    Posts
    4,377

    Default

    The scary thing about boats is the amount of material that never gets onto the water ... not to mention the time spent making stuff that never gets onto the water ... and I'm not referring to mistakes - moulds, patterns, offcuts, steam boxes, etc

    Richard

Page 2 of 37 FirstFirst 123456712 ... LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •