Advice please on fitting A-Frame.

kerny · 30 June 2015, 15:12

I'm going down to Marine Fabrications on Saturday morning to have a new double A-Frame made up and need some advice on the best way to bolt the front feet to the deck.

There is no void between the marine ply so my only choices are bolt straight through the deck and out underneath the hull or Maximus has got some brackets with captive bolts which can be cut into the deck then glassed over which is adding another expense which I really want to avoid if possible.

Your thoughts please on which is the best way to go about this as I want to get it right first time due to the amount of money I will be spending, thanks.....

Here's some pics of how the hull is made and also where the marine ply is fitted over the hull which shows that I have not got any room to play with also if I drill to near to the tubes then it is only fiberglass as the marine ply deck is fitted flush further in by about 23 cm.

two stroke mick · 30 June 2015, 16:06

One possible solution however it may be laughed at here. get a SS plate circa 200mm by 100mm and 4mm thick. have a bolt welded to it so it points upwards. bore a hole in the deck to recieve the head of the bolt. Screw and sika flex the stainless plate into postion on the deck. The sika flex to do the job of holding the plate in place. The screws are in place to allow the sika flex to cure/ go off. Make sure the screws are no so long that they go through the hull. Bolt said SS A frame to the recieving bolt.

Why are you getting rid of the old A Frame?

TSM

Phil M · 30 June 2015, 17:10

look here for the method I used recently.

Phil M

kerny · 30 June 2015, 17:18

Quote:

Originally Posted by Phil M

look here for the method I used recently.

Phil M

That's why I put the pics up of the build Phil M there is no void at the stern where the A-Frame is going to be bolted too.

Still an ingenuous idea though if you do have a void

Phil M · 30 June 2015, 18:28

Sorry, missed that bit. In that case, the plate and stud method with a stack of sika will be your best bet i reckon. Pre-rebuild, my frame just had a big self tapper in each leg and that lasted at least 15 years before it started to pull out so a plate and numerous screws should do the job.

Phil M

gtflash · 30 June 2015, 20:17

Can you not bond a plate in? Aluminium or stainless with or without a stud pointing outward?

Revenges used to bond Ali block into a frame areas and then drill and tap. Obviously that's a little risky in your situation

kerny · 30 June 2015, 21:37

Quote:

Originally Posted by two stroke mick

Why are you getting rid of the old A Frame?

TSM

It was a folding A Frame TSM which snapped due to fatigue while going down the sound of Mull probably because of all the rattling it was doing, my fault for insisting on having one fitted so that I could get my rib in my garage....... but that's another story.

A1an · 30 June 2015, 21:52

For the little extra the glassing work would take I'd be glassing in some plates Steve.

Price it up, you might be surprised.

Through hull would make me uneasy.

A1an · 30 June 2015, 22:02

Some pictures Ive shamefully stolen from someone else's thread but it shows that glassing in is not a major undertaking. Quality finish too.

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kerny · 30 June 2015, 22:02

Quote:

Originally Posted by A1an

For the little extra the glassing work would take I'd be glassing in some plates Steve.

Price it up, you might be surprised.

Through hull would make me uneasy.

Thanks A1an, that's what Maxi as well as Chris Caton suggested so that makes 3 of you, so maybe that's the way I will go. Mike Whitham here I come

Superjetjim · 30 June 2015, 22:04

Quote:

Originally Posted by A1an

For the little extra the glassing work would take I'd be glassing in some plates Steve.

Price it up, you might be surprised.

Through hull would make me uneasy.

+1 glass in some plates with bolts presented from underneath, or use thicker plate and tap holes / use stainless bolts

Xk59D · 30 June 2015, 22:09

i'd be having a go at that myself, not a complicated job.

go on, get the grinder out

kerny · 08 July 2015, 20:26

Just a quick update on this, just got Imogen back from Marine Fabrications with a new A-Frame fitted and two wing back seats. I'm very pleased with the outcome and service from them just need to get the feet glassed over on the deck.... a few pics....