Laminating lead sheet to MDF etc

[martinw]

Dear All,

I would like to laminate 1/16" lead sheet to 3/4" MDF. No.. I am not in the funeral business, but a 30 year life-span for the laminate would do just fine.

I'm thinking of de-greasing the lead sheet, lightly abrading it, and using phenol-formaldehyde wood glue, putting the assembly in a vacuum bag ( about 0.7 bar vacuum), until the glue does its stuff.

After that, it would be really good to be able to rout rebates through the lead and into the MDF.

The rebates would be attempted with a hand-held router. Given that the subsequent joints will be MDF to MDF, I think it would not be a good idea to use greasy cutting fluids on the lead because the greasy stuff will migrate into the MDF. Yeah, I know lead is going to stick to even the sharpest router bit.

Help me dudes, or tell me it is impossible...

Best Wishes

Martin

[Geof]

It's impossible.

There, happy?

Your glue will not stick very well to lead; actually it will not stick at all and will form essentially a vacuum bond.

Lead can be cut fairly successfully with a router but it is practically certain you would simply peel the lead off the glue which would remain as a film on the MDF.

For what earthly reason are you wanting to attach lead to MDF? To build a radiation proof cupboard to climb into when there is a nuclear attack?

[ger21]

Just use contact cement like you would with plastic laminates. You can still put it in the vacuum bag to increase the bond strength. Route with solid carbide down cut spirals, the bigger the better.

I've never worked with lead, but we do this all the time with decorative aluminum, brass and copper laminates.

[martinw]

Originally Posted by Geof It's impossible. There, happy? Your glue will not stick very well to lead; actually it will not stick at all and will form essentially a vacuum bond. Lead can be cut fairly successfully with a router but it is practically certain you would simply peel the lead off the glue which would remain as a film on the MDF. For what earthly reason are you wanting to attach lead to MDF? To build a radiation proof cupboard to climb into when there is a nuclear attack?

Dear Geof,

Phenol -formaldehyde glue bonds are OK between MDF and steel, according to the glue peoples' bumf.

I can't see any reason why lead shouldn't be OK either. After all it is softer and less likely to suffer shear from thermal differential expansion, and anyway, the shear would be (IMVVHO) less in a softer material.

I am encouraged by your optimistic routing suggestions and will venture forth, and report back.

One last thing,

No, I am not building a "Duck and Cover" haven , under my staircase, to protect my small tribe from an imminent nuclear attack from bonkers terrorists. Others have suggested that the threat of "Dirty Bombs" is laughable.

It is.

Best wishes,

Martin

[brunog]

Martin,
Urethane glue might be a better choice. It's commonly used to assemble wood to brass and wood to aluminium to make hand tools.

best regards

Bruno

[martinw]

Thanks Gerry and Bruno for the glue suggestions.

The reason I suggested phenol formaldehde is because I have some lying around. The data sheet says it's OK for metal as long as you use a special primer ($50 per litre plus shipping as it turns out). At that price, I've rather gone off the idea of using it, so I'll try polyurethane to start with.

I've never used PU before, but I know it is moisture curing. I read somewhere that when using it for biscuit joints , it is a good idea to really lightly mist the biscuit with water. In my vacuum bag, there isn't going to be a whole lot of moisture available, so I'm thinking of misting the MDF before assembly. Any comments would be much appreciated.

Best Wishes

Martin

[Laff Riot]

If it would be easier to laminate the lead to aluminum which in turn is already laminated to the wood this might be an option.

http://www.wrisco.com/nualum.htm

Its plywood not MDf but it is marine grade and should last longer.

Even better - if you dont need the wood in there would be AlumaCor - which is aluminum mounted to a plastic core and another piece of aluminum on the back. This should last longer than the cockroaches.

We use high test silicone in combination with 3m exterior tissue tape (cheap!) to attach aluminum sheets / letters to the Alumacor and I have yet to have one come back.

[martinw]

Dear Laff Riot,

Thanks for that. I'm going ahead with lead plus MDF using polyurethane glue. My vac.pump was playing up so I have not had time to vac. laminate yet, but a sample glued up with cramps worked really well.

Best wishes

Martin