Selway Fisher Clyde 18

[biglad]

Re: Selway Fisher Clyde 18

Thanks John- I'll get some ordered and see how I go.

It's a while since I last used it, but I'm sure I used a set piece of arbomast and used that to dab it off.

[John Meachen]

Re: Selway Fisher Clyde 18

That was always the way,but it comes as a surprise to many.

[biglad]

Re: Selway Fisher Clyde 18

I've been drilling the holes in the windows over the last couple of nights. I've got some epdm washers coming to fit between the head of the machine screw and perspex.

Thinking about bedding the fittings now... Will arbormast (non setting butyl) be OK for everything? I have some higher stress items (engine mounting bolts, bow roller and mooring bollard) and some lower stress items. Will drilling a hole for the bolt, and a countersink to take some arbomast be ok for all items, or should I drill oversized holes, fill them with thickened epoxy and then re drill to the correct size? Backing pads are mostly 12mm ply.

I read about only sealing the exterior side, so that moisture doesn't become trapped.

[biglad]

Re: Selway Fisher Clyde 18

I made the bottom boards for the cabin, and the w/c. I've put a ply lid on it, as I have the foam cushions made to cover the whole of the cabin, so it can be used as a flat sleeping space. The back rests fit between the two side cushions. I've still to make the slats that will fit between the bench fronts- you can see from the photo the notches where they'll fit.

20230425_200710.jpg

[John Meachen]

Re: Selway Fisher Clyde 18

I don't know a huge amount about EPDM and it's variations,but have found that my encounters with the commonly supplied version is a bit soft and squidgy.I hope yours is a bit nearer the consistency of a tap washer or the like.
Arbomast is a sound choice for just about any sealing task,but if you believe there is a risk of wracking strains opening the bolt holes then it would be a sound move to seal the holes with something.Varnish alone would be better than nothing and epoxy,followed by drilling out, would give the ply a great chance to wick in some durable sealant.

[biglad]

Re: Selway Fisher Clyde 18

I think I'll drill oversize holes for the fittings that are under stress- outboard mounts, cleats, bow roller and sampson post.

I'll cover a scrap piece of ply with plastic tape and wedge it under the hole to be filled. I'll fill the hole with epoxy and hope it goes ok!!

[neil.henderson]

Re: Selway Fisher Clyde 18

I think I'll drill oversize holes for the fittings that are under stress- outboard mounts, cleats, bow roller and sampson post.

I'll cover a scrap piece of ply with plastic tape and wedge it under the hole to be filled. I'll fill the hole with epoxy and hope it goes ok!!

Alternatively you can just slap a short length of gaffer tape across the underside of the hole - then fill hole with epoxy and don't apply a lot of pressure to the top. I did this through the cabin top of a 32' motor cruiser I used to own. I ended up with a nice smooth epoxied hole in the cabin top. All the best.

Regards Neil

[biglad]

Re: Selway Fisher Clyde 18

Sounds a neat way Neil- thanks.

How oversize should the hole be? 10mm for a 6mm (M6) thread? I guess it makes sense to (try to- might be awkward) put some unthickened epoxy down the drilled hole with the bolt/machine screw to take up any slack, otherwise arbomast in the hole/countersink might be ok

[neil.henderson]

Re: Selway Fisher Clyde 18

Sounds a neat way Neil- thanks.

How oversize should the hole be? 10mm for a 6mm (M6) thread? I guess it makes sense to (try to- might be awkward) put some unthickened epoxy down the drilled hole with the bolt/machine screw to take up any slack, otherwise arbomast in the hole/countersink might be ok

Yes, 2mm of epoxy all around the hole sounds enough but I wouldn't go any less - the objective here is to ensure that the ply is sealed (I think) so we need to make sure that happens. Remember to mark where the hole centre needs to be by drawing multiple lines across it before drilling the large hole.

Regards Neil

[biglad]

Re: Selway Fisher Clyde 18

Thanks Neil- appreciate the hints and tips!

[biglad]

Re: Selway Fisher Clyde 18

I've got the bolts into the grab rails fitted. I did it (with the help of my lad) by inserting the machine screw through from the inside with a large washer on it, dribbled some sloppy epoxy /microfibers down the hole (before and during as the bolt was fitted) and then poking some more down the hole, round the threads of the bolt. The washer and nut were then fitted from the top, and then a timber plug was epoxied in place.

The parts that are under stress I'm going to drill oversize holes and then re drill for the fittings. Ive ordered some 404 filler as per the west docs. The west documents say to use more epoxy round the threads of the fixings and on the mating surfaces. I have painted the boat so I'd need to sand back to timber if I'm going to do this. I can always touch up any epoxy squeeze out clean ups etc. For the fittings that are through bolted, I wonder if a small countersink and arbomast in the epoxy bushing would do a better job of keeping the water out, and also making it easier for the fittings to be removed in the future for repair/replacement.

For the fixings that are under no stress eg nav lights, I'll use just arbomast and for the ones that I want to stay put eg deck locker hinge I'll drill over size the first 2/3rds and fill with epoxy, before screwing the fixing home.

Does this sound OK?

[John Meachen]

Re: Selway Fisher Clyde 18

A small countersink would do no harm.Its more important to wind some old arbomast around the threaded portion of the bolt as it passes through the joint region as the thread forms a helical leak path if left bare.The act of tightening the fastening will squeeze the mastic in all directions and improve the chances of a leak free installation.If you are fortunate enough to have bolts with a length of plain shank,the countersink full of mastic will be enough.

[biglad]

Re: Selway Fisher Clyde 18

Thanks John- appreciate the advice. Think I'll skip the countersink and get some mastic round it to keep the water out. On the fittings that have a good surface bonding area, I'll sand the paint off and epoxy it to the boat.

[biglad]

Re: Selway Fisher Clyde 18

I was out working on the boat today and drilled 4 holes for the samson post. Slight issue is that they are quite close to the inboard edge of the backing pad/ spine framework. The holes on the baseplate (and what I have drilled) are 120mm athwartships, and 200mm would give me a more even spread. I've had a look at chandlers online on can't see any other posts with as wide a base as I need. Deck cleats seem to be fitted to run fore and aft, which doesn't really help me. Is there any other fittings which might do this?

I could try a stainless fabricator and ask them to remove the plate that is on the post I have and weld a larger plate onto it. I'm not overly concerned about the holes I have- I can fill those and they'll be under the plate, which I might epoxy to the deck.

[Steamboat]

Re: Selway Fisher Clyde 18

What about a really thick oversized plywood baseplate under the post with the post bolted to the baseplate? Edges could be chamfered to ease the transition from the wood baseplate to the deck. Might look too chunky though.