What epoxy to use prior to installing new screws to deck?

davethedog

davethedog

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Morning all,

I have seen lots of YouTube videos etc for fitting new deck hatches where the screws are in different ,ovations on the new hatches. So they all say for the new screw holes, to drill oversize holes and then fill with epoxy resin prior to then drilling the correct size holes for the screws.

So, what epoxy is recommended for that please? As needs to be strong but also not too brittle.

Dtd
 
Screws? I use bolts and nuts. I just make the holes, rub some epoxy into the hole with a cotton bud, wait for it to go off, and then Abromast BR to seal the hatch. Just in the middle of doing the task again now - the deck had a slight camber so built it up with epoxy mix. Hatch from China for heads.
 
Screws are what the hatch was fitted with before and looks like I can not get to the underside of the hatch area to use bolts
 
davethedog said:
Screws are what the hatch was fitted with before and looks like I can not get to the underside of the hatch area to use bolts
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If that's the case I would use epoxy mix with 404 colloidal silica. But that's a big boat (and I presume with big hatches) to be using screws.

Edit: sorry, not colloidal silica. That's the 406 stuff I have been using.
 
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The professional way is drill oversize hole through cored deck. Use bent nail in drill to take out a bit of core all round. Mix epoxy (West System is fine and available anywhere) with colloidal silica to thicken to peanut butter consistency (you can also use milled glass if you want it much stronger for any reason) and fill the hole. Then leave for a day or two to fully cure and drill your hole. There are short cuts that save some time and usually cause no problems but thats the full package
 
If it is indeed a part of the deck where there is a core between 2 layers of GRP then yes route out the core around the hole and fil;l with epoxy and filler. However if in fact the deck area is solid GRP then you need only drill a samller hole and run a tap into GRP for the screws you are using. (old GRP will be as strong as new epoxy to tap into. ol'will
 
I have done this a couple of times but never sure that the hollowed out section is properly filled with epoxy mix. Do you use a thinner mix rather than near peanut butter consistency?
 
davethedog said:
Morning all,

I have seen lots of YouTube videos etc for fitting new deck hatches where the screws are in different ,ovations on the new hatches. So they all say for the new screw holes, to drill oversize holes and then fill with epoxy resin prior to then drilling the correct size holes for the screws.

So, what epoxy is recommended for that please? As needs to be strong but also not too brittle.

Dtd
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Hi I know this post is a few weeks old but as someone who has built many, many GRP boats i’m guessing the reason people are advising this is the stop the gel coat splintering out?
Have fitted many many windows, hatches and other fitting screwed onto a gel coated grp finish, drill the hole the correct size and countersink through the gel.
 
marcusgillies said:
Hi I know this post is a few weeks old but as someone who has built many, many GRP boats i’m guessing the reason people are advising this is the stop the gel coat splintering out?
Have fitted many many windows, hatches and other fitting screwed onto a gel coated grp finish, drill the hole the correct size and countersink through the gel.
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I think its probably for two reasons. One to give a solid area so a screw with nut the other side does not crush the core and two to prevent water ingress to the core material causing rot to the balsa or ply inside. I agree that a counter sink on a self tapping screw will often prevent splintering problems. If there is no core then nuts and screws suffice with clearance hole and window sealant. I don't use self tappers on ports or windows so no need to countersink. But most of this has been covered yonks ago in this post.
 
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Given that it is winter, the best product also depends on temperature. In the summer, fast epoxies overheat and bubble in the holes. If it's cold, fast is you friend. Read the specs.

Also, fill the holes from the bottom up. It is very easy to trap air, and big bubbles are weak.
 
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