Deleted
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Post by Deleted on Jun 7, 2020 17:45:48 GMT
question about wooden sections: on the ark2 sheet there are slats of 22 x 30, 40, 50 and 70mm and on the ark4 sheet the slats for the frames and beams are 22 x 45 and 55mm ... is this strictly necessary or measures can be unified
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Post by Admin on Jun 7, 2020 23:35:49 GMT
Hi..It is always a good idea to stick with the plans but the general rule is you MUST NOT go smaller or lighter but you can go Bigger or stronger...so never go smaller
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dan
New Member
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Post by dan on Jun 17, 2020 15:56:10 GMT
I don't see in the plans where to place screws. Are screws necessary? Can we use only epoxy? If we must use screws, where do we use them?
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Post by jaysen on Jun 17, 2020 16:41:47 GMT
Look at some Setka builds for examples. Basically the stews are used in two places. 1. Secure gussets to frames 2. Secure exterior sheeting frames/stringers.
Based in the amount of bend required on exterior sheeting the screws really should be used. Relative to the gussets, the screws assure alignment through epoxy cure allowing for movement after initial hardening.
While the temptation is to remove the screws. You would need to over drill and fill holes (over drill needed to ensure threads cleared out). That’s a LOT of work for no real weight savings.
If you’re concerned about metal in the hull, remember that you are glassing the entire exterior and epoxy coating then painting the interior. If you take the time with the process that metal won’t see light of day again. If it does it will look exactly the same as when you put it in.
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martellmarine
Junior Member
Husband & wife team building boat #71.
Posts: 61
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Post by martellmarine on Jun 17, 2020 18:18:57 GMT
Think of the screws as clamps or an extra pair if hands. They are only needed until the epoxy cures. Depending on what is being held in position while being glued, other options could include pin nails, narrow crown staples and even masking tape. They are not critical to the integrity of the structure. You will find though that it will be convenient to leave some in and bury them under epoxy filler and fibreglass. Another way to use screws for clamping is with washers. We often use what we call 'half penny washers' 18mm dia with a hole smaller then the countersunk head. Test fit before buying your clamping washer. Cheap steel ones will do. Drill clearance holes in your stock being glued for optimum pressure. An alternative to filling screw holes with epoxy is to use wooden plugs. On exterior surfaces they tend to leave less print through impressions in your paint job. A word of warning: If you intend to remove screws, do not use stainless screws, use regular steel screws. If there is some glue around the thread and if they are left in too long, stainless screws have a tendency to snap. They are weaker than regular steel construction screws. I make it the very first job next morning/day after using screws in a gluing process that I intend to remove, to either completely remove them or back them off a turn (you will often hear the audible crack of the glue join breaking) and then tighten again. The best way to avoid snapping off any screw head is to manually (hand held screw driver) do the initial backing off. If you just get in there with a battery driver screw gun and pull the trigger, you will find the initial twisting shock does the damage. The longer the screw the more tendency to snap. I personally will be trying to find ways to limit the use of screws.
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dan
New Member
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Post by dan on Jun 17, 2020 18:35:07 GMT
I've been trying to find a video of someone building the frame and have not been successful.
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Post by jaysen on Jun 17, 2020 21:11:17 GMT
I've been trying to find a video of someone building the frame and have not been successful. The Facebook page for the class posts a few. Here’s on Setka builder that has lots of vids (this link is further along). /?d=n You can find links on the class website “builders blogs” page as well.
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Post by Admin on Jun 18, 2020 5:36:39 GMT
There is reference to screw spacing in the latest 01 Builders Blog from Janusz on the website. The design calls for SS screws that are filled before glassing as you will see on all the SETKA Blogs and videos. Building the JIG to support Frames can take different forms....drawing the FRAME shape onto your plotting board is simply on a grid with careful measurements, then carefully cutting all frame components and laying onto the drawn shapes. Good luck!!
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brucel
Junior Member
Posts: 54
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Post by brucel on Sept 10, 2021 18:30:56 GMT
@don for screw length for the 1800 screws 4mmx30mm. If we are using 9mm ply + 22mm stringers = 31mm. Which due to the shaping of the ply, stringers and counter sinking the screws can result in the screw tips penetrating the interior of the hull, this has two effects a) creating 1000s of penetrations in the last ply skin b) creating a lot of additional work trimming the tips which results in an uneven surface to for finishing which needs to be addressed. With the 10mm ply you have a little more room. Would it be possible to reduce the screw length for 9mm ply construction to use 25mm/1" screws? Or should I direct this question to Janusz?
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Post by Admin on Sept 18, 2021 6:36:56 GMT
Hi This is an interesting question as no other builders have made comment and none talk about 1000 small penetrations??? so best check with Janusz...as I would not normally say shorter screws and I cannot decrease spec...but if as you say you have penetrations that is a pain?? ..all the best...
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brucel
Junior Member
Posts: 54
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Post by brucel on Sept 20, 2021 21:36:27 GMT
Janusz says grind off screw tips with angle grinder, uses screws as per plans. "It often happens that we cannot buy screws of the correct length. Then it's better to buy longer ones. The end of the screw that protrudes inside the boat must be cut. This is best done with an angle grinder. Better use 31.7mm screws. 25 mm will be too short"Might try and get real 30mm screws vs 1.25" screws we have here in North America. Or buy a wee little grinder.
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martellmarine
Junior Member
Husband & wife team building boat #71.
Posts: 61
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Post by martellmarine on Sept 21, 2021 0:39:31 GMT
Hi This is an interesting question as no other builders have made comment and none talk about 1000 small penetrations??? so best check with Janusz...as I would not normally say shorter screws and I cannot decrease spec...but if as you say you have penetrations that is a pain?? ..all the best... Dan Turk mentions that he had penetrations that he had to grind off. I must say Don that it seems weird that on the one hand you have said that a professional boat builder building for a client can build a 5.80 with staples but someone like me who is a professional boatbuilder building a 5.80 for himself must now use screws that are too long and must have the tips ground off! A 25mm screw out performs a staple in this situation. Surely there needs to be a better conversation around things like this based on application and material availability around the world...? Cheers
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martellmarine
Junior Member
Husband & wife team building boat #71.
Posts: 61
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Post by martellmarine on Sept 21, 2021 0:55:29 GMT
Janusz says grind off screw tips with angle grinder, uses screws as per plans. "It often happens that we cannot buy screws of the correct length. Then it's better to buy longer ones. The end of the screw that protrudes inside the boat must be cut. This is best done with an angle grinder. Better use 31.7mm screws. 25 mm will be too short"Might try and get real 30mm screws vs 1.25" screws we have here in North America. Or buy a wee little grinder. View AttachmentI must say that in 40 years of boat building I have never seen a designer spec a screw so long that it had to be cut off with a grinder, let alone several hundred of them. Seems bizarre! Either the wrong screw was spec'd or the wrong material dimension was spec'd. Imagine the hours added to the construction now... A 25mm #8 screw has IMMENSE strength in tension in a softwood like pine, let alone in shear. There will be less work involved increasing the thickness of the stringers and chines to 25mm than going through the mess of grinding off all of those screw tips, and then filling the damage each one leaves behind. Cheers
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Post by captdan on Sept 21, 2021 1:49:46 GMT
Hi This is an interesting question as no other builders have made comment and none talk about 1000 small penetrations??? so best check with Janusz...as I would not normally say shorter screws and I cannot decrease spec...but if as you say you have penetrations that is a pain?? ..all the best... Dan Turk mentions that he had penetrations that he had to grind off. I must say Don that it seems weird that on the one hand you have said that a professional boat builder building for a client can build a 5.80 with staples but someone like me who is a professional boatbuilder building a 5.80 for himself must now use screws that are too long and must have the tips ground off! A 25mm screw out performs a staple in this situation. Surely there needs to be a better conversation around things like this based on application and material availability around the world...? Cheers Yes, I had to shorten the screws because of the screws being too long. I did use a grinder to start with but then changed to a Dremel oscillating tool ( link below ) because it induced much less heat. My thought process / end results were that the extra heat from the grinder was burning the epoxy from around the screw. us.dremel.com/en/products/-/show-product/tools/multi-max-mm35
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brucel
Junior Member
Posts: 54
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Post by brucel on Oct 25, 2021 3:44:02 GMT
Stringers follow up. From the B&B 3D Don posted higher up in this chat. This is my cut list material list. No I dont have 6000mm boards I will be scarfing them, I’m using reclaimed Douglas Fir. 40mmx135mm x 3000mm boards. (It’s North American so actually should be in inches but do not want to confuse things any more) qty long mm high mm depth mm 2 3030 50 22 2 5900 70(40+30) 22 2 5860 30 22 2 5850 50 22 2 5750 30 22 2 5710 50 22 In comparing the original hand drawn and BnB there is a différence. The 70mm runs from Frame E to S but drops to 40mm on the orignal plans and 30mm (comment is later dropping to 30mm) on the B&B 3D plans but looking at hull #2 it sure looks like 70mm all the way. Do any of the builders have a cut list like this? I checked a few sites and could not find one. Please link you blog post if you do for the rest of us kit builders. UPDATE- See 42:00min mark on B&B video youtu.be/0AuIdhvyFssI will be leaving them longer maybe plus 100mm and not planning to size till I have the frames to check the actual notching finial size. Edit Nov 10th 2021. It looks like the 70mm from S to E has been done a few different ways. 70mm - 70mm cut down from the transom to S and E to Steam OR 40mm, with 30mm laminated between S and E.
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