Bonding in consoles

[BruceB]

I am looking at fixing in my new console and for various reasons am considering bonding it in. Assume I know nothing about working with Glassfibre (not very far from the truth), how would I do this and what would I need to make a good job of it?

[jwalker]

Just be aware that ultimately the bond between your consol and the boat will be the fibreglass cladding to plywood deck surface and fibreglass to wood is not always the best bond. The fibreglass cladding will only be about 2mm thick and you will need to take some of that back in your preparation.

[Hightower]

Bonding is good, but I would also use a mechanical way of securing too, like using ss wood screws and penny washers

[BruceB]

I looked at fixing in my console and am a bit worried at the sides that I will end up puncturing the outer hull with the fixing screws, the console is the full width of the inner space.
I was considering grinding off the external fixing flange on both sides and leaving it front and rear. Then screwing the two remaining flanges to the deck with sikaflex and normal and then bonding the whole console to the deck on the inside.
Not sure yet which way to go but I know I definitely don't want screws sticking through the hull.

[Hightower]

I would hazard a guess that the deck will be at least 19mm thk so 19mm screws won't stick though. I'd use the longer ones inboard and shorter ones around the outside. The other option is to increase the footprint of the console by making an internal wooden ring that fits just inside the console, if this was bonded too it would make for a much better constuction because of the increased surface area to deck.

[BruceB]

The console end right at the join between the deck and hull where it looks like the deck is tapered to fit to the angled hull shape. I will need to carefully measure but rough and dirty measurements tonight (it was raining!) look like the screws go through the tapered edge of the deck and will end up outside the hull, it doesn't look much thicker than the thickness of the outer hull at this point which seems to be around 10-12mm of Glassfibre.
I need to measure more carefully to be sure (quite hard to do so and match inside and outside measurements on both sides of tubes) but I am looking at a backup up plan just in case.
The really worst case is to move the console back to where the hull is wider but this would mean sitting very far back in the hull.

[Erin]

I would screw it down if you can, but if not, then if it's properly bonded down to the deck with f/glass then it won't be going anywhere. The chances of you peeling a whole layer of glassfibre off the top of the plywood deck in one go are pretty slim. The sheer surface area involved and the rigidity of the console would make it nigh on impossible without some tremendous force being applied.

[AndrewH]

Originally Posted by Erin

would make it nigh on impossible without some tremendous force being applied.

Something like the force of several tons of water as you stuff the bow at 25 kts (or more) ... perhaps ...

Granted, we all hope for Bruce's sake that this is unlikely but the old line of "hope for the best, plan for the worst" has a lot of merit. IMHO the risk is not of full shear debonding, but more of a peeling off debonding. Given the height of a console, leverage is going to be an issue. Therefore anything to stop any lifting round the edges (like the judicious application of screws and penny washers as suggested by Hightower) has to be a good idea.

I'd just feel happier with belt AND braces

[Bigmuz7]

I asked my dealer about this on my last rig out, but he poo poohd it and suggested just bonding to the deck and screw fixing would be fine. To his credit on my last two rigs this has worked fine. I still feel that a grp flange round the console base would have been better though .. not least of all to stop the dreaded water ingress to the under deck. Next time I will demand it !!

[BruceB]

How is it screwed to the deck with no flange?