Jump to content

Silicone Sealant, or Grease? And drilling holes...

Recommended Posts


I am new to the Forum, but not to Land Rovers.


I picked up a 90 TD5 earlier this year, in a bit of a state (insurance Cat D write off), and paid someone to get it on the road & fit a safari snorkel.

Since then, I have started changing it into the sort of vehicle which I need.

1st step was to add window grilles over side windows, ended up doing the back too. Sourced them from Simmonites.

2nd was to ditch the Tornado alloys & (4 different brands) 5 tyres which had seen better days, replaced them with 16x7 modulars & Cooper Discoverer AT3 235/85

I am about to embark on the next phase & am wondering several things, which I hope you will be able to assist with:

Firstly - Hole drilling: I have to drill holes in the body capping (Flatdog Ladder & Mantec swingaway carrier) - so I know I have to start with a pilot hole, but how small? Then make the hole bigger in stages. The Mantec suggests that I need to drill these out to 11mm - so I'm wondering what size I can get away with starting with & what sizes of drill I can go up in?

Also on hole drilling - I have some 3mm chequerplate from Paddock, and intend to use their allen bolt things, as they're countersunk. Reckon I'll be ok with a 7mm hole - I am thinging that I'll do a 3mm pilot on the alu & then straight to 7mm - will this cause problems?

The only other thing is under the chequerplate - grease between the plate & the wingtop, or silicone sealant about half a cm from all the edges?

Lastly, here's my previous history:

110 hardtop diesel (E reg) - sold

109 Safari petrol S2a - 1966 - sold

109 Hardtop petrol S2a - 1966 - Sold

ES Discovery 300 Tdi (R reg) - Sold

90 TD5 CSW in Epsom green - T reg - daily drive

VW Golf GT Tdi - about to be sold.

I'll post pics soon.

Link to comment
Share on other sites

I think you could start with a 6mm hole and enlarge in 2/3mm steps up to the required final size, make sure you have a decent centre punch to create a spot to start the drill in. I'd go with Silicone rather than grese although nothing is strictly necessary, have you considered self adhesive neoprene tape? its available in different widths and thickneses.....


Link to comment
Share on other sites

Hole drilling

If you read "our project" http://forums.lr4x4.com/index.php?showtopic=75880 You will see hom many holes were drilled. Both in steel and aluminium alloy.

I used a 3mm drill for all starter holes, then to 5mm for the pop rivit holes. Or as required.

I don't have anything under the checker plate on any of the added on checker plate to bodywork.

before you drill the checker plate for the Allen bolts. Check the drill size needed on some scrap

I suggest you buy more than one 3mm drill. I broke some at the least expected time. Candle wax on the drill end when drilling aluminium alloy helps to keep the drill that bit sharper longer.

Link to comment
Share on other sites

Welcome to the forum :)

Sealant (either silicone or PU) rather than grease, but it's not strictly required. The Neoprene recommended above sounds like a good solution

When drilling I first centre punch, then drill with a 4mm. Then open the hole up to required size.

I use a 4mm rather than a 3mm or 1/8th because I find I break the smaller drills too easily, especially when drilling stainless with a cordless. Breakage is less of an issue in the drill press

You only need a pilot hole to be larger than the flat at the tip of the next drill, so you can go from a 4mm to an 11mm without any others in between, as long as the tip of the 11mm drill bit is 4mm or less.

Make sense?

Link to comment
Share on other sites

If you want to use any sort of adhesive, I'd go for U-Pol "Tiger Seal".


With Tiger-Seal there's truly no need for screws/bolts/rivets to be involved. It holds-in bonded windscreens [which are a structural component of most post-1990 cars] just fine.

Squirt, bond, and relax!

Link to comment
Share on other sites

Cool. Thanks.

Been enjoying being back (where I belong) in a Landy.

I like the neoprene idea.

I don't want to glue it down, just keep the moisture out.

Drilling - I've got DeWalt extreme2 HSS bits, having discovered that my old HSS bits are no longer of much use.

"Our Project" - looks good, wil have a read through.

Thanks all. very helpful. :)

Centre punch before drilling - yes, I remember that from metalwork at school in the 80s. How about mask tape for marking stuff? or just use a sharpie pen?

Link to comment
Share on other sites

I use masking tape and a biro as the fine line allows for decent accuracy. A sharpie would also be adequate

Before anyone mentions engineering blue and a vernier height gauge that's hardly the tolerance required for this kind of task

Link to comment
Share on other sites

I haven't got that many shots of the TD5 online, this shot was taken in Devon. I went off to photograph a force 11 storm, and when I returned, its twin had arrived, both CSW T reg TD5s :)

This was when it still had its alloys, and not the nice steel wheels:


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy