Securing console/seat to the deck.

chorscroft · 04 June 2008, 17:52

I am planning on moving the console on my brig rib, and adding a jockey seat behind it, partly because of weight distribution and partly because bench seats are useless in any sort of sea.
Currently the console is bolted to nuts embedded into the deck. My plan to secure it was to use self tapping screws and sikaflex, but the console doesn't have a flange.
Is it alright to screw it from the inside edge as opposed to the outside edge of the flange?
What size of self tappers should I use?
I've never tried anything like this before - is there anything that could go badly wrong?

Thanks in advance

Conor

- My plan is to position the console, clean and lightly sand all around and under it. Sikaflex it to the deck. Let it dry for a bit. Drill several pilot holes the same diameter as the screw minus the thread. Put sikaflex on each screw and screw it to the deck. Let it dry and go boating!

martini · 04 June 2008, 22:49

If you do a search on this site on the subject you will find a very recent thread regarding an MCA report which will show you how this can go VERY wrong!

However, without cutting up your deck, sikaflex and self tappers is about the best you can do.

chorscroft · 05 June 2008, 07:07

And what size self tappers should I be using?
Do you screw them in with a screwdriver or a drill?
Is a standard wood drill bit alright for the pilot holes?
How far apart should they be spaced?
Would you recommend washers?

Regards

Conor

Andy JC · 05 June 2008, 11:21

Not so much from experience but mostly info I've picked up on similar threads:

And what size self tappers should I be using?
No sure about that one

Do you screw them in with a screwdriver or a drill?
Drill first then finish off by hand (ooer!)

Is a standard wood drill bit alright for the pilot holes?
Should be fine

How far apart should they be spaced?
Around 10cm apart

Would you recommend washers?
Yup and sikaflex

Experts will be along soon to correct me I'm sure

Cookee · 05 June 2008, 12:14

Quote:

Originally Posted by martini

If you do a search on this site on the subject you will find a very recent thread regarding an MCA report which will show you how this can go VERY wrong!

However, without cutting up your deck, sikaflex and self tappers is about the best you can do.

Apart from Fibreglassing it down!

martini · 05 June 2008, 16:13

Quote:

Originally Posted by Cookee

Apart from Fibreglassing it down!

What about bonding together with resin or similar? Grind the deck and the flange of the console back to fresh glass where they meet, mask off the rest of the area and get as much resin on there as you can.

I'm fitting my console and seats very soon, using 6mm A4 woodscrews with cup washers, prob at around 2-3" centres. My advantage is that the deck isn't down yet so I can put in structural timbers in underneath to give the screws something to bite in to.

chorscroft · 05 June 2008, 18:38

What is the advantage of this? Strength?
From reading other threads self tappers and sikaflex seem to work well enough, why would I need any extra strength?

Also could some of you take a look at this: http://cgi.ebay.co.uk/Single-Jockey-...QQcmdZViewItem

Is it worth me buying as a jockey seat?
How hard would it be for someone who as never fibreglassed before to make a fibreglass flange around it?
How hard is it to get a seatback preferably with a grab rail aswell?

Regards

Conor

martini · 05 June 2008, 20:24

In my experience Sikaflex is not the be all and end all. I've pulled things apart before without too much difficulty.

If you havent already, you should read this - http://ribworld.com/forum/showthread.php?t=24667

chorscroft · 05 June 2008, 20:33

What does it mean by surface preparation?
The deck of my boat also has those non slip granules - should I be sanding them down till I remove them?
The bottom of the console is already bare fibreglass.

Regards

Conor

P.S. My steering cable will need to be lengthened - is it possible to disconnect the cable from the rod and the helm unit and attach a new one in? How hard is it to do this and could someone explain to me how.

Regards

Conor

jwalker · 05 June 2008, 21:27

Have a read.

chorscroft · 05 June 2008, 21:34

Any idea what the thickness of brig decks are?
Does it weaken it if I go completely through it?
My console doesn't have a normal outer flange or set holes and I will be screwing using a sort of inner flange - should I be drilling through the console and deck at once or should I drill the console and then use it as a guide for the deck?

Regards

Conor

jwalker · 05 June 2008, 22:18

Quote:

Originally Posted by chorscroft

Any idea what the thickness of brig decks are?

No idea. Is it ply? If you find it to be relatively thin, use more screws. If you find it to be fibreglass then you may need to rethink because screws are not good in fibreglass because of its structure and characteristics.

Quote:

Does it weaken it if I go completely through it?

No.

Quote:

My console doesn't have a normal outer flange or set holes and I will be screwing using a sort of inner flange - should I be drilling through the console and deck at once or should I drill the console and then use it as a guide for the deck?

It won't matter but after drilling the pilot holes, drill the holes in the console to be a clearance size for the screw otherwise the screws will not tighten the console down to the deck.

chorscroft · 06 June 2008, 07:12

By clearance holes do you mean that the screw should drop through them with just the head of the screw holding it in place?

Also any help advice on how to change my steering cable.

Regards

Conor

prairie tuber · 06 June 2008, 08:47

Use either 3M 5300 marine sealant or 3M 4200 marine sealant if going through plywood, rather than sikaflex. Sikaflex will is not friendlly to the adhesives used in plywood.

Cookee · 06 June 2008, 09:43

JW's post is very good advice - If you are in any doubt of your DIY skills don't do it get a pro!

What can go wrong - the screws can pull out, you can puncture an under deck fuel tank, if you only bond to where it touches it is a very small "contact patch" and could pull the top surface of whatever you are fastening to. Also you have no data on how the deck was built or what condition it's in! Sorry to sound a little negative, but it's better to give it the best chance of sticking!

chorscroft · 06 June 2008, 17:58

Quote:

Originally Posted by martini

What about bonding together with resin or similar? Grind the deck and the flange of the console back to fresh glass where they meet, mask off the rest of the area and get as much resin on there as you can.

If I were to stick down my console with a type of resin or glue, what would I use?
Would this be stronger than self tappers?
How to you remove the console if you want to change it after?
My console has a solid base of bare fibreglass, does that change anything?
I read in a booklet for brig I had that the deck is marine ply, will there be a layer of fibreglass under the gelcoat, but above the deck?

I'm coming round to thinking that this could be an easier and safer option, as I would really rather do it myself and save what I assume would be a considerable amount of money.

Regards

Conor