Hi, I've recently bought my first caravan (Eccles ruby) and just had a solar panel fitted about 4 weeks ago, I've been down to check it out in storage and noticed water leaking through into the cupboard, it looks like the two plastic nuts that the cables go through were loose. I finger tightened them and sealed the cable box and nuts with unibond extreme repair sealant. Is this Sealant ok on my van roof?, thanks in advance.