Prep for lizard skin

[mdutton11]

I am 3 weeks away from lizard skin. Have already done most wiring so it will take a little extra work. My question is that I have hear LS does not stick well to silicon. EdwardB suggested using aluminum tape (I assume HVAC tape) over the slinicon. I have also heard instead of silicon I should use bostik 1100fs to seal any remaining gaps and the LZ will stick. What about the seams I already used silicon on. Do I have to grind / sand it down or should I put alum tape over the seams. I have Bostik on order for the remaining. All help is appreciated.

[GFX2043mtu]

You are correct that it wont stick to silicone. It also doesn't like non sanded surfaces. all surfaces should be sanded no finer then 600 so it has something to bite when applied. As far as the seams go it's depending on how many and how messy they are. If the silicone is all over and spread far from the seam area I would personally scrap and sand it back to the joint. How you do it doesn't matter much as the lizard skin goes on thick and will hide scratches. In all honesty before the lizard skin I only sealed obvious gaps where panel edges meet and you can see light from the other side. The lizard skin is thick when it goes on and can be seal sealed after it cures. Just note most carpet glues also don't like silicone. I personally used a modified polyurethane and Sikaflex for joints. One last word of advice don't let it fully cure for days before pulling the tape. If you pull it when it feels solid it pulls easily and leaves clean lines. 141611141612141613

[edwardb]

Since I was mentioned I will comment. I agree completely Lizard Skin, like a bunch of other products, won't stick well to silicone. If at all. Not sure of the context of the question where I suggested aluminum tape. Perhaps as a seam sealer where there are gaps? Which works well. But if we're talking about silicone that's squeezed out of the joints, smeared around, whatever, probably not the right answer. I agree, clean it up. I've used both silicone and the various polyurethane based products without noting much difference. So I've opted to go back to only silicone. But I clean the joint completely during assembly so it's not an issue for adhesion. I see some build pictures where product is squeezed out all over and just left that way and kind of cringe. Neatness matters. If the width of the Bostik 1100fs used for sealing isn't too wide, probably OK.

I agree all surfaces should be roughed up. I use pretty heavy grit just to be sure and the Lizard Skin is so thick it will cover any scratch marks. So scuff away. I also agree about pulling the tape when the Lizard Skin is still wet. Since the usual Lizard Skin application is two products (sound and thermal) my practice is to double tape. Pull the first layer after the first coat, wait for it to cure, then pull the second layer after the second coat. If you wait for the Lizard Skin to dry you will have to cut at the edges to prevent lifting. Not fun and not necessary.

[rich grsc]

The correct answer is, you shouldn't use so much silicone that it's all over the place to start with. It isn't "a little is good, a lot is better"!
Like Paul said, "neatness matters".

[mdutton11]

Thanks guys - exactly the info I was looking for. Silicon seepage is pretty minimal and now I will scuff it out with the rest of the aluminum. There are a few gaps that are probably 1/4 inch that are the ones I am thinking of (see pic). EdB - your build threads have helped inspired me and helped me through many build issues. I was referencing your lizard skin application on "the other" forum when I was asking about the aluminum tape. Better to scuff and get rid of the silicon and let the lizard skin do its job.

141619141621

[phileas_fogg]

I like Dynatron (smile.amazon.com/gp/product/B005RNFBMC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) for filling the larger gaps. Use painter’s tape to keep the mess under control, & use your finger to get a nice fillet. Dries with just a hint of “give” & you can paint it.


John