SolrSearch and escaping ampersands


We're having some issues with ampersands and SolrSearch.

Namely when we search using a facet with an ampersand in the search value it will work the first time but if then you select another facet it will fail on the ampersand, it no longer encodes it to %26. Afterwhich we get an exception thrown by solr.

So my question is, how to escape an amperand in Solr.

Thanks in advance,