Grab handles

[Stemar]

Jazzcat's a very comfortable boat in calm seas, but 20 knots of wind over tide in the Solent gets her dancing a jig, and that wide open cockpit, so lovely at anchor, becomes a bit of a hazard. I want to install some grab handles so whoever isn't helming has something to hold on to. The bulkhead is about 18mm ply covered with GRP, and any nuts on the inside are going to be unsightly. Would 4 or 8 screws be strong enough, or do I just have to accept that safely has to trump aesthetics?

 

[Poignard]

Not for me to tell you what to do, but I would never trust woodscrews for that application.

I was horrified to find the coachroof grabrails on my Twister were secured by woodscrews driven up from underneath,

I refixed them with stainless steel bolts (in counterbored and plugged holes), large washers and dome nuts.

I'd rather gaze at a neat row of dome nuts than a transom disappearing into the distance.

 

[oldgit]

Have installed several grab handles to aid the wifes movements around the boat.
Used some hefty stainless self tappers into substantial glassfibre with a dab of CT1 in the joint.
Bought some genuine stainless handles at B&Q or Wickes which were much better "value" than those in my local chandlery.
Despite the somewhat "substantial" loads placed on them they remain intact.

 

[Boathook]

I would bolt. 99% of the time screws would be fine, but it is the 1% when someone grabs the handle and puts extreme load on.
Could always use dome headed nuts for the bolts to give a better finish.

 

[Rappey]

I would be happy with chunky screws to retain the athetics of the interior.
Try pulling a screw out of ply with a 3ft crowbar and you will understand the holding strength of a screw.

 

[Poignard]

I would be happy with chunky screws to retain the athetics of the interior.
Try pulling a screw out of ply with a 3ft crowbar and you will understand the holding strength of a screw.

18mm thick ply.

That means 16mm (5/8 inch) of screw thread.

Doesn't seem much to me.

Of course he could improve the holding power by wetting out the screw holes with epoxy but even so....

 

[johnalison]

My HR 34 is not dissimilar to the roughly contemporary Naiad 331. Although I (naturally) prefer my HR, I do like the grab handles on the Naiad which are placed at the front of the cockpit above the bulkhead. There is not much to be lost from trying screws, but if they tear out they could easily be replaced with bolts, which I would fix with domed nuts inside, which wouldn't look at all bad.

 

[Fr J Hackett]

18mm thick ply.

That means 16mm (5/8 inch) of screw thread.

Doesn't seem much to me.

Of course he could improve the holding power by wetting out the screw holes with epoxy but even so....

Screw from inside with the screw going into the shoulders of the handle, maximise the length of the screw and pre drill the wooden handle.

 

[Mister E]

Countersunk bolts on the inside and dome headed nuts on the outside would be the neatest.

 

[johnalison]

Countersunk bolts on the inside and dome headed nuts on the outside would be the neatest.

I hadn’t thought of it that way round. A number of fittings within my boat have domed heads, which made me think that way. Whatever floats your boat, so to speak.

 

[RunAgroundHard]

... Would 4 or 8 screws be strong enough, or do I just have to accept that safely has to trump aesthetics?

Yes they would be strong enough if they are as large as you can fit. Soak the holes with thinned epoxy glue using a cotton bud a few times until it starts to thicken and sort of stays in the hole. The screw in wood screws, clean up overspill. The exact procedure is stated in West How To Manuals. Also Gudgeon Brother book on boat building has shear test tables that show wood screws done in this method are extremely strong. There is no need to have unsightly bolt heads on the inside. No need to take my word on it, the research has been done for you. At the force required to pull out the screws, your hand will be ripped out the wrist. Obviously drill the pilot holes to the correct size for the screw type et cetera.

 

[Tranona]

No10 pan head 15mm selftappers with epoxy in the pilot hole will be fine.

 

[William_H]

OP has not specified how many screws for each end of the grab bar. if it has a flat plate with screw holes then if he can add more places for screws then (enough) wood screws would do the job. Or even add a flat plate or wood block with multiple screws in to bulkhead that the handle can be bolted to.
Just a few other options however bolted right through would still be best bet. ol'will

 

[Tillana]

Screws aren't great for possible side loading as they can snap. I'd go with bolts.

 

[Neeves]

Does Jazzcat have a cockpit roof?

We had a 'similar' problem and I installed ring bolts in the roof, 4 of them in a rectangular configuration. We then strung 10mm double braid through the 4 bolts. Two of the bolts were close to the cockpit/saloon bulkhead.

I could stand in the cockpit hands over head and 'hanging' from the rope and be perfectly safe looking forward through the forward saloon windows.

The rope makes moving around the cockpit safe, the rope is not a hazard to heads and makes a good clothes line (when at anchor). We also hung our LJ, tethers and harnesses from the rope when at sea.

Obviously if Jazzcat has no cockpit roof - no use to you

We also had 'U' bolts at about waist height in the cockpit/saloon bulkhead, either side of the patio doors, (as a means to be clipped on when in the cockpit), so the 'U' on the outdoor side of the bulkhead and as suggested used dome nuts on the inside.

Jonathan

 

[Fr J Hackett]

No10 pan head 15mm selftappers with epoxy in the pilot hole will be fine.

Bulkhead is 18mm thick so 15mm selftappers won't even reach the handles, unless you and the OP is thinking of using something with a flange on the outside in stainless or similar. I was thinking conventional wooden grab handles and screwed in from the interior with the longest screws possible something like 8s, 10s or 12s.

 

[Stemar]

There is not much to be lost from trying screws, but if they tear out ...

If they do, Madame may have a different opinion...

Thanks for the comments, everyone. We aren't talking about extreme weather, just for when things get a bit bumpy.

I think I'll look for handles with three screws per end and use nice chunky screws. I'm hesitating about epoxying them in, as I might want to get them out one day and I very much doubt Madame's grip would be strong enough to pull even one screw out.

 

[Tranona]

Bulkhead is 18mm thick so 15mm selftappers won't even reach the handles, unless you and the OP is thinking of using something with a flange on the outside in stainless or similar. I was thinking conventional wooden grab handles and screwed in from the interior with the longest screws possible something like 8s, 10s or 12s.

Yes, I was assuming stainless handles as suggested in post#3. I used just that for the crash rail in front of the cooker between 2 bulkheads. Of course wooden handles would be different, but I would use screws through the handle into the ply and epoxy. Countersink the screws and plug.

 

[Fr J Hackett]

Yes, I was assuming stainless handles as suggested in post#3. I used just that for the crash rail in front of the cooker between 2 bulkheads. Of course wooden handles would be different, but I would use screws through the handle into the ply and epoxy. Countersink the screws and plug.

Horses for courses but I think using Wooden ones screwed from inside the boat would be stronger with the head of the screw providing a bit of load spreading even more if a panhead screw and washer was used. Screwing through the handle into the bulkhead is imo weaker but obviously neater in that there is nothing to see inside the boat.

 

[Tranona]

It may well be less strong, but is it strong enough? If epoxy is used as suggested in the West manuals the bulkhead and grab handle effectively become one with the addition of a metal strut.