Interesting and useful fix I created for a low load fixing into a sandwich deck

[Concerto]

In side my Fulmar a previous owner has fitted stained plywood panels under the side decks in the main cabin. To hold the inside edge to the deck he screwed a rebated piece of timber. He drilled into just the inside layer of glassfibre of a balsa core deck and then used brass woodscrews. Unfortunately the screw thread was too coarse to hold in the relatively thin glassfibre, so he then drilled the holes larger and used shortened plastic rawplugs to hold the screws. Over time these had stopped holding the screws and the panel dropped. I tried adding extra padding with matchsticks for the screw to grip on, but this failed.

Today I created a simple permanent solution. Removed all of the old match sticks and rawplugs. Squirt a little water into each hole and then insert matchsticks covered with Gorilla glue (the water is the catalyst for the glue). This expands over a couple of hours to 4 times its volume. Once set I cut off any excess material flush with the glassfibre. Any void in the balsa core is filled and the hardened glue and matchsticks makes a perfect material to screw into.

 

[Moodysailor]

I've used the same for low load fixings on the interior - it's surprisingly effective as you say.

For higher load items in a similar context, I have used bighead fastners epoxied to the interior grp, then used regular bolts/screws.

 

[Poignard]

Good stuff, Gorilla Glue.

 

[Sea-Fever]

How very PBO ?

 

[Refueler]

In side my Fulmar a previous owner has fitted stained plywood panels under the side decks in the main cabin. To hold the inside edge to the deck he screwed a rebated piece of timber. He drilled into just the inside layer of glassfibre of a balsa core deck and then used brass woodscrews. Unfortunately the screw thread was too coarse to hold in the relatively thin glassfibre, so he then drilled the holes larger and used shortened plastic rawplugs to hold the screws. Over time these had stopped holding the screws and the panel dropped. I tried adding extra padding with matchsticks for the screw to grip on, but this failed.

Today I created a simple permanent solution. Removed all of the old match sticks and rawplugs. Squirt a little water into each hole and then insert matchsticks covered with Gorilla glue (the water is the catalyst for the glue). This expands over a couple of hours to 4 times its volume. Once set I cut off any excess material flush with the glassfibre. Any void in the balsa core is filled and the hardened glue and matchsticks makes a perfect material to screw into.

Exterior grade Gorilla Glue ..... actually the generic version is PU Glue - sold in any builders merchants is Seawater Proof and excellent for bedding in parts ... gap filling .... bonding literally anything to anything ...

The big bottle is half the price of the smaller bottle !! But its same product.

The spraying of water is actually not always necessary ... PU glue will react with moisture in the air but its expansion is less. The more water added - the greater the expansion, lighter the infill weight.

Its a common use glue in model building especially with todays Foam board planes etc.

I've been using PU glue for bedding stanchions and various to deck for years.

Uses :

Here's a plastic nose cone that is prone to damage on landing the model ... but filled with a 50-50 water / PU glue mix ... its strong for just a couple of grams extra :

For creating a 'core' filler .... then I would suggest a 20% water - 80% PU glue mix ..... and then fill the 'core area' to about 30% height ... allow the mix to foam and expand .....

If its a hole all way through the deck - then you need a plate with clingfilm pressed up under to close hole ... pour in the mix - again about 30% height ...

There is a 'white' version of PU Glue - but that is Interior grade and not suitable for boat use.

 

[Poignard]

I wanted to put up a shelf in our tiled bathroom. The tiles are fixed to breeze blocks .

At first the plastic wall plugs I was trying to use simply rotated in the friable beeze blocks when I tried to screw into them.

I wetted out the hole and applied a little Gorilla glue to the plugs before inserting them and leaving the glue to expand and set.

After that i was able to tighten the screws without the plugs moving.

 

[Refueler]

Its worth checking out your local B&Q .. Wickes ... Do It All .... etc. - PU glue is sold under various names.

Just remember :

White is interior grade
Brown is exterior grade.

 

[LittleSister]

I just feel sorry for all those poor gorillas.

 

[LadyInBed]

I just feel sorry for all those poor gorillas.

They have Gorilla farms where they milk the bile to make the glue. The Chinese pay a fortune for it, come to think of it, so do we! ?

 

[Moodysailor]

PU/Gorilla glue is surprisingly versatile - we had a damaged mainsheet traveller last season that was through-bolted through a cored deck. When we removed it we found that the core hadn't been removed when it was fitted, so there was some core damp/ damage that needed repairing.

As it was mid-season and we wanted to continue to use the boat, we rigged the mainsheet to a central (origional) padeye, I opened the holes slightly and used some wooden dowel with the GG to fill the holes to make the boat watertight temporarily. Because of the damp in the core it set perfectly, I was able to sand the plugs back flush when set and we enjoyed the rest of the season before a fix was done. As we had to do core repair it was easy to drill out the plugs, and the temporary fix kept the boat dry all season.