How to mount timber base to hull.

[WalrusLike]

I want to move my isolator switch off the side pocket and on to the hull up high just under the gunnel. Two reasons are: out of the weather, and can be reached from outside when on trailer.

I was thinking of just using silastic to bond the piece of timber on to the hull. The timber piece is what I am going to screw the switch to.

I could also use liquid nails. Presumably a better job would be lay some glass over the timber but I am not experienced with glass and it is not really necessary.

Any suggestions?

[chris69]

Hi warlruslike it depends how long you want it to last,if its painted it will last longer and you could arildite it to stick it on or yer it would be better glassed over and to the boat,you will have to scuff the area up to get good adheasion as the glass or gelcoat will be waxed so a good wipe with some acetone on the glass or gelcoat before you sand it will help other wise it will clog your sand paper but only wipe the area that you are sticking too,mark out the spot and just tape up outside that spot and use 80 grit,this will help what ever you use be it liquid nail or resin or arildite stick better,you could use some rod epoxy if you have some to stick it on and paint the wood before hand to seal it,cheers Chris.

[Noelm]

from my experience, any sort of 'glue" like silicon and liquid nails and so on are tempory at best, it will hold for a while, but it will fall off, either leave it where it is, or do it properly.

[Nathan Tuskes]

id use something like starboard or something similar that wont rot or fallapart(your kidding yourself if u think just painting timber will make it lastin a boat) and then sikaflex(marine grade about 4-6bucks more) it to the boat(so no holes in any structural partsof the boat opening up a water ingress point into core materials then just useshort ss screws to fix your isolator to the starboard panel

[fandtm666]

personally i would grab a small mix of epoxy glue to fix
it to the hull and then it can also be sealed properly

http://www.biasboating.com.au/product_p/3312a.htm

[WalrusLike]

Thanks fellas. Food for thought there.

Whereabouts can you get Starboard? I looked it up and it looks interesting. Didn't know it existed. I also need to put a panel in the cabin to mount cigarette sockets into. It might be the go for that too.

[Noelm]

don't think you can glue Starboard all that well, but I could be wrong, most good boat shops should be able to put you onto some.

[chris69]

Dont use that Starboard it warps horrible product.

[Scalem]

I am trying to picture what you are doing, I guess using the epoxy resin that I used in my "Shingles will Jarr anything Loose" thread would be too fluid ... But using the same approach, I would give a sheet of marine ply a coat of resin to seal it (once you have jigsawed to the shape you want as a base), same as I did for my pedestal bases, and once that is dry apply a lighter coat when you attach your base up inside the gunnel.

Scalem

[bigjimg]

Walrus drop into a chandler and grab small kit of epoxy glue,Norglas/International/Technirez,all good glues.Also grab a small tin of flowcoat with catalyst.Get your piece of cut to size timber,ply or block of wood,and sand it up smooth on 1 face and the sides,rough on the other face.Apply three coats of flowcoat with a fine paintbrush allowing time to cure between coats.An advantage if you can apply a 6mm radius to the edges with a router or trimmer beforehand.Once coated wet sand or leave as it is,myself being fussy I would sand and polish.Then rough sand the area on your hull where your going to mount the block,mark it out first.Mix up your epoxy glue to the correct ratio and butter it onto your block being careful to apply a thin even layer.Then gently press into position but don't press to hard and squeeze the glue out,you want to keep a thin layer of glue in the joint.The glue will suck to the surface so a couple of strips of masking tape to hold in place until the glue goes off will help.That joint will be 100% water tight and if your good any glue that has squeezed out just trim with a sharp stanley knife at about the 3-4hr mark when it has gelled.Don't try and wipe it off wet you will just make a big sticky mess.Hope this helps.Jim

[WalrusLike]

Thanks guys... I might try Jim's idea... To be honest I thought this would be a 'yeah I did that on mine' kind of thing.... Am I the only silly bugger that wants to mount things where there is no mount point?

That's me.... Doing it oddly, and/or doing it wrong...

Yesterday I was toying with the idea of filling half an inch of my motor well with silastic to make the drain hole the new lowest point..... Boy it sure would be ugly but I think it would work fine.

PS. Do you flowcoat the front and the back of the board?

[timddo]

Why not use chopping board material and silkaflex it to the hull.

[peterbo3]

You need boatboard. Starboard by another name. It does not rot, swell or distort, is UV stable & can be sawn, drilled & machined like wood. Cannot be fixed with any known adhesive so SS fittings are the go. I would suggest 19mm thick. Available cut to size here:
http://www.dotmar.com.au/boatboard/b...ne-sheets.html

Or I may be be able to cut you a piece if you are close to Albany Creek.

[deckie]

Why not use chopping board material and silkaflex it to the hull.

Coz chopping board is polyethylene and glue's wont work. Not even a quality epoxy will work on it properly.
Peterbo, my understanding is he cant screw it, coz it'll obviously go straight thru the hull so he wants a backing glued on first to screw into. Who knows tho, i might be about go right off course

You can kind of "glue" it when poly/stargoard/kingboard etc is a relatively large and flat contact area, but its really the surface contact area holding a weak bond together rather than any sort of proper adhesion. Some guys claim their slab of "baitboard" stuck with sika to the transom gelcoat as a mounting pad has "glued", but thats the surface area effect holding it, slightly lever it and it'll come off fast.
Basically if its nylon/poly type plastics glues are just sealants used with proper fastenings. A 6 inch square flat plate onto a flat surface for instance will grip but something small or little surface contact wont last. Starboard/King board whatever u want to call it is in the same league.
Personally i still reckon ply has many advantages coz so easy to work with, as long as it is treated properly first it will last, can be shaped/glued/screwed with nothing fancy. Sika/4200 is pretty good stuff but still need to rough up surfaces. Best/easiest/cheapest ply treatment i reckon is to get a small tub of poly resin and thin with about 30-40% styrene monomer, all easy to get from a local glass supplier. Slap a cpl coats on so it soaks right into the grain. OR thin some flowcoat and do same, dry then flowcoat and sand smooth for a pro finish. Acetone no good over about 5-10% as a thinner. Whilst epoxy is better it can get damn messy, expensive, etc as a ply treatment. Whilst poly/epoxy isnt the best adhesion if the ply backing is roughed/gouged, the gel/flowcoat on hull taken back, then epoxy as a glue is a permanent fix. I've fixed small treated and flowcoated ply blocks onto hull with sika tho and that seems to last ok. Obviously if using epoxy its on for good and will take the gel/flowcoat off with it if removing, but thats one of the beauties of glass/gelcoat its easy repaired to new. Vibration on boats can rattle anything off thats under load. To last Q of whether to flowcoat back of it...nope, rough up both surfaces in contact tho, preferably tape off and remove hull gel/flowcoat and it'll stick like shit to a blanket. A compromise might be 3M 5200, more permanent/stronger than 4200 or sika but easy to use and have a chance of getting it off better than epoxy. Once agin tho, no good on "baitboard" type products. If using ply backing tho dont forget to seal the screw/bolts holes with sika/4200.

Walrus...how u going to get access to back of the batt switch ? Not sure how you;re thinking of setting it up. Bit lost. I understand u need a backing plate that must be somehow GLUED to the actual hull and cant use screws, but how u going to screw the switch onto the backing plate whilst maintaining access to the back of it ? Is there maybe part of the superstructure where gunwhale comes inboard where u can use a holesaw and mount flush ?..maybe near helm/console ?

[WalrusLike]

Wow. Thank you guys for your enormous and detailed help. This forum is fantastic because of guys like you.

I was about to say that I owe you helpers a beer.... But then I realized that if I bought a beer for you all at say a meet and greet then I would be broke because so many on here have helped me so often.

Perhaps one or two at a time?

Deckie the switch is like this:

http://www.bepmarine.com/home-mainme...battery-switch

It can be surface mounted with wires in from the side. I was assuming that I could unscrew the isolator switch from its current position down low on the side pocket then mount it on the newly installed mounting board up against the hull just under the overhang of the gunnel. Your correct that is why I want it... I can't screw the switch to that thin part of the hull... It might be a very bad idea.