This is what everyone recommends for sealing the dropper on a classic truck or car and it seems good but it's really dirty. Be sure to use masking tape on the surfaces you don't want, as trying to peel it off will pull it off and ruin what you just put on. Just do the prep work and take your time.
Clean Sheets CLN-CS100: 100 Disposable Superior Mixing Pad (12x12) for Toughest Jobs - Clear
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